Missed the Provisional Patent Deadline?Options for Filing a PCT Application
Executive Summary: Missing the twelve-month priority deadline after filing a U.S. provisional application does not necessarily foreclose international patent protection. A PCT application filed within the following two months may retain the provisional’s priority through a timely, supported restoration request. Filing directly with WIPO’s International Bureau as receiving Office (RO/IB) allows applicants to seek restoration under either the “due care” or “unintentional delay” standard without a separate RO/IB restoration fee, although ordinary PCT fees remain payable. Restoration based on due care generally receives broader recognition, particularly before the European Patent Office. Where an RO/IB restoration is recognized, a second restoration petition and associated fee ordinarily are unnecessary; other jurisdictions may require separate local relief or decline to recognize the restoration. National offices and courts may also review whether restoration was properly granted. Restoration does not cure defects in priority entitlement or inadequate disclosure in the provisional application. Applicants should therefore act promptly, document the reasons for the delay, assess their intended countries and filing routes, and confirm the requirements and deadlines governing recognition or further relief.
Introduction
A founder files a U.S. provisional patent application, develops the product, and plans to pursue international protection. Then the calendar delivers an unwelcome surprise: the twelve-month filing deadline passed last week. The founder still wants to file under the Patent Cooperation Treaty (PCT). Is it too late?
The applicant ordinarily may still file a PCT application that meets the requirements for an international filing date. The critical question is whether the application can recover the provisional's priority benefit. The additional two-month restoration period is not an outer limit on obtaining an international filing date. Without an effective priority claim, patentability must be assessed using the actual international filing date, with the resulting prior-art and disclosure consequences. PCT procedural deadlines require a separate analysis, discussed below. Patent Cooperation Treaty art. 11(1)–(3), June 19, 1970, 28 U.S.T. 7645, 1160 U.N.T.S. 231.
The missed priority deadline may still be curable. The PCT permits restoration of priority in qualifying cases when the international application is filed within two months after the priority period expires. But a short delay does not make restoration automatic. The applicant must satisfy a restoration criterion applied by the receiving office, comply with the restoration procedure, and determine where the resulting decision will be effective. Regulations under the Patent Cooperation Treaty r. 26bis.3(a)–(g) (Jan. 1, 2026) [hereinafter PCT Rules]; PCT Rules rr. 49ter.1–49ter.2.
For a client who is only one week late, the immediate task is to preserve the remaining filing opportunity while investigating the facts. The practical strategy should distinguish three questions: Can the client still file a PCT application? Can the client recover the provisional application's priority date? And will the offices serving the client's target markets recognize that restoration? A further question arises after a successful RO/IB request: must the client restore priority again in each national phase? Usually no, where the designated office recognizes the grant. A fresh request may be necessary where the grant has no effect, and a local remedy must actually be available. PCT Rules rr. 49ter.1(a)–(b), (g), 49ter.2(a), (h).
What the missed deadline actually means
A provisional application ordinarily supports a claim to its earlier filing date in a qualifying U.S. nonprovisional application filed within twelve months. Clients often call the next filing a “conversion,” but the usual procedure involves a new application claiming the earlier filing's benefit. The provisional is ordinarily regarded as abandoned twelve months after filing and cannot be restored to pending status after that period. Restoration addresses the later application's entitlement to the earlier date; it does not revive the provisional. 35 U.S.C. § 111(b)(5); 35 U.S.C. § 119(e)(1), (3).
The PCT provides a coordinated international application process, followed by national or regional proceedings in the jurisdictions where protection is sought. WIPO does not issue a worldwide patent. The receiving office handles the international application's initial processing; an International Searching Authority conducts the international search; national or regional offices ultimately decide whether to grant patents. Choosing WIPO as the receiving office does not replace those later proceedings. World Intell. Prop. Org., PCT FAQs, question 1 (Aug. 2026) [hereinafter PCT FAQs].
Restoration also cannot cure an inadequate provisional disclosure. For U.S. benefit, the earlier application must adequately disclose the claimed invention under the applicable statutory requirements. A feature first added in the PCT application does not acquire the provisional's date merely because priority is restored. That distinction matters when the product has changed substantially during the intervening year. 35 U.S.C. § 119(e)(1). Counsel should therefore review both the deadline and the substantive support for the claims the client actually needs.
Restoration also does not establish who is entitled to exercise the priority right. The Paris Convention gives that right to the person who duly filed the first application or that person's successor in title. A founder's personal provisional followed by a corporate PCT filing, an omitted co-applicant, an intervening assignment, or a corporate restructuring calls for an entitlement review. Counsel should determine whether any necessary succession to the priority right occurred before the international filing date under the applicable law, preserve the transfer or name-change evidence, and examine incomplete employment agreements or later-executed assignments. Restoration itself does not supply missing entitlement, disclosure support, or national formalities. Paris Convention for the Protection of Industrial Property art. 4A(1), Mar. 20, 1883, as revised July 14, 1967, 21 U.S.T. 1583, 828 U.N.T.S. 305.
An appropriately worded declaration under PCT Rule 4.17(iii) can address the international applicant's entitlement, as of the international filing date, to claim the earlier application's priority. Rule 51bis.1(a)(iii) permits designated offices to require proof where the applicants differ or the name has changed. That authority is limited by Rule 51bis.2(iii): when a compliant declaration is contained in the request or submitted directly to the designated office, further documents or evidence cannot be required unless the office reasonably doubts the declaration's veracity. A declaration records the asserted entitlement; it does not itself create a missing transfer. PCT Rules r. 4.17(iii); PCT Rules rr. 51bis.1(a)(iii), 51bis.2(iii).
The remaining window is short and has several requirements
For receiving-office restoration, the international filing date must fall within two months after expiration of the priority period, ordinarily within fourteen months of the provisional filing. Within that restoration window, the applicant generally must submit the restoration request and reasons, include or add the priority claim, and pay any restoration fee the receiving office requires. Evidence should preferably accompany the request, although the office may invite further evidence within a reasonable period. PCT Rules r. 26bis.3(a)–(f).
At an office that charges a restoration fee, Rule 26bis.3(d) allows the office, at its option, to extend the fee-payment period by up to two months after the ordinary restoration deadline. This discretion concerns payment only. The application filing, restoration request with reasons, and any necessary addition of the priority claim remain subject to their applicable deadlines. RO/IB currently charges no restoration fee, as explained below. PCT Rules r. 26bis.3(a)–(e).
Counsel should calculate the deadline under the applicable calendar rules rather than substitute sixty days for two months. Month-end dates, office closures, holidays, and the receiving office's applicable time zone can affect the calculation. PCT Rules rr. 80.2, 80.4–80.5. A request for early publication can also shorten the otherwise available restoration period once technical preparations for publication are complete. PCT Rules r. 26bis.3(e).
For the one-week-late client, the sensible filing package includes the PCT application, the provisional priority claim, an express request for restoration, and a supported explanation of what happened. Counsel need not postpone filing until every supporting record has been collected, but the timely restoration request must contain a factually sufficient statement of the reason for the missed filing. A bare request promising an explanation later is insufficient. Supporting declarations and additional evidence may follow where permitted or requested. PCT Rules r. 26bis.3(b), (e)–(f).
Late filing must also be distinguished from an omitted priority claim. A PCT application filed within the ordinary priority period but missing the priority information presents a different correction problem. The rules allowing correction or addition of a priority claim do not generally excuse filing the international application itself after the restoration window. PCT Rules rr. 26bis.1(a), 26bis.3(a), (c).
Why filing directly with WIPO can matter
The USPTO, acting as receiving office (RO/US), applies the unintentional standard. WIPO's International Bureau, acting as receiving office (RO/IB), applies both unintentional and due-care standards. That difference can influence the later geographic value of a restoration decision. The USPTO's own guidance identifies RO/IB as an option when restoration under due care is desired. U.S. Pat. & Trademark Off., Manual of Patent Examining Procedure § 1828.01 (9th ed., rev. 01.2024, Nov. 2024) [hereinafter MPEP].
“Filing directly with the International Bureau” means submitting the PCT application to WIPO in its capacity as receiving office, rather than submitting it to the USPTO as receiving office. In an ePCT filing, the applicant selects the International Bureau as the receiving office. Using WIPO's ePCT platform alone does not establish that choice, because the platform also supports filings with other participating receiving offices. PCT FAQs, questions 6–7; World Intell. Prop. Org., PCT Applicant's Guide, annex C (IB), “Filing of International Applications in Electronic Form” (Aug. 31, 2026) [hereinafter PCT Applicant's Guide].
RO/IB is available to applicants with the required nationality or residence in a PCT contracting state. An appropriately qualified U.S. patent practitioner can represent an eligible U.S. applicant before RO/IB; Swiss counsel is not required merely because WIPO is in Geneva. Nor must the client first file a U.S. nonprovisional application before filing the PCT application. PCT Rules rr. 19.1(a)(iii), 19.2; PCT Rules r. 83.1bis(a)–(b).
If the PCT application was already filed with RO/US within the additional two-month period and counsel determines that due-care consideration is needed, the applicant may promptly request forwarding to RO/IB under Rule 19.4(a)(iii). This route requires agreement between the offices and the applicant's authorization. RO/US may decline a request after substantial processing has occurred. A qualifying transfer preserves the original receiving-office receipt date for filing-date purposes, but does not restart the restoration-request period. Counsel should arrange the transfer and restoration submissions promptly; selecting RO/IB at filing is preferable when the need for due-care consideration is already known. MPEP § 1828.01; PCT Rules r. 19.4(a)(iii)–(c); PCT Rules r. 26bis.3(e).
Rule 19.4(b) also permits the forwarding office to charge a fee equal to its transmittal fee. Any such forwarding charge is distinct from RO/IB's restoration fee, which remains zero. PCT Rules r. 19.4(b).
For inventions made in the United States, counsel must separately check foreign-filing restrictions. An existing foreign-filing license may authorize the submission. Filing may also be permissible after six months have elapsed from an earlier U.S. filing if no secrecy order applies, but the scope of the earlier disclosure and any newly added subject matter require attention. A thirteen-month-old provisional does not eliminate that analysis. 37 C.F.R. §§ 5.11, 5.15 (2026); MPEP § 1832.
RO/IB applies alternative standards, not two cumulative hurdles
The two standards ask different questions. Unintentionality concerns the applicant's intent when the priority period expired. A deliberate decision to forgo timely filing followed by a change of mind is insufficient. Due care asks whether reasonable precautions were taken for this particular application despite the eventual failure. Both applicant and representative must satisfy the applicable due-care inquiry. World Intell. Prop. Org., PCT Receiving Office Guidelines ¶¶ 166I–166K (last visited Sept. 8, 2026) [hereinafter RO Guidelines].
The published default for an office applying both criteria is to assess due care first and, if due care is not established, assess unintentionality, unless the applicant requests otherwise. Satisfying both is not a prerequisite to restoration. A due-care finding generally encompasses unintentionality, but an unintentional-only finding does not establish due care. RO Guidelines ¶ 166H.
The distinction rewards careful factual investigation. Relevant evidence may include reliable docketing and backup procedures, staff training and supervision, and whether the failure was isolated. General assertions that the practice is careful are inadequate. Prompt action after discovering the omission is useful operationally, but does not itself establish the precautions taken before the deadline. RO Guidelines ¶¶ 166J–166M.
Consider two versions of the same missed week. In the first, the founder intended to file but misunderstood the deadline and had no reliable reminder process. In the second, an established docketing process failed through a documented, isolated error despite appropriate supervision and backup measures. The first account may support an unintentional request. The second may justify pursuing due care as well. Neither outcome follows solely from the length of the delay; each depends on the facts and supporting record.
Where the evidence supports it, counsel can expressly seek due-care restoration and unintentional restoration in the alternative. The request should explain the chronology, identify the cause of the missed filing, and connect the supporting evidence to the requested standard. A request should not assert precautions that were absent or describe a deliberate choice as accidental.
Restoration submissions should be drafted with later public access in mind. The statement of reasons, declarations, and supporting evidence generally are transmitted to the International Bureau and become publicly accessible through PATENTSCOPE after international publication. Counsel should include the facts and evidence needed to satisfy the applicable criterion while omitting unnecessary personal, medical, financial, privileged, or commercially sensitive information. A confidential label alone does not establish an exception to public access. PCT Rules r. 26bis.3(h)(iv); PCT Applicant's Guide, International Phase ¶ 5.066 (Apr. 23, 2026).
Under Rule 26bis.3(h-bis), the applicant may make a reasoned request that specified documents or portions not be transmitted. The receiving office must find that the material does not obviously inform the public about the application, that disclosure would clearly prejudice a person's personal or economic interests, and that no prevailing public interest favors access. All three conditions must be met. Information already in the IB's file is subject to the separate public-access restriction procedure under Rule 94.1(e). If essential due-care evidence is withheld from the record available to designated offices, national-phase review becomes more likely and equivalent information may have to be supplied again. PCT Rules r. 26bis.3(h-bis); PCT Rules r. 94.1(e); PCT Applicant's Guide, International Phase ¶ 5.067 (Apr. 23, 2026).
Before wholly or partially refusing restoration, the receiving office must provide an opportunity for observations. The process uses Form PCT/RO/158 for an intended refusal and Form PCT/RO/159 for the decision. A grant under unintentionality coupled with a refusal under due care is a consequential partial refusal. Counsel should read the recorded criterion, not simply report that “WIPO restored priority.” PCT Rules r. 26bis.3(g)–(h); RO Guidelines ¶¶ 166R–166S.
RO/IB charges no restoration fee, but the PCT filing still has costs
RO/IB currently charges no fee for requesting restoration of priority. That published zero-fee position applies whether the request invokes due care, unintentionality, or both. It is not a small-entity discount or a waiver requiring proof of hardship. PCT Applicant's Guide, annex C (IB), “Fee for Requesting Restoration of the Right of Priority” (Aug. 31, 2026). The PCT permits each receiving office to set its own restoration fee, so this result should not be generalized to every receiving office. PCT Rules r. 26bis.3(d).
For comparison, WIPO's current restoration table lists RO/US fees of $2,260 for an undiscounted applicant, $904 for a small entity, and $452 for a micro entity. Those amounts concern a restoration request before RO/US; they are not additional charges imposed on every PCT application claiming a U.S. provisional. World Intell. Prop. Org., Restoration of the Right of Priority by Receiving Offices (RO) and Designated Offices (DO) Under PCT Rules 26bis.3 and 49ter.2, entry “US,” n.14 (Aug. 19, 2026) [hereinafter Restoration Table].
The ordinary RO/IB filing charges remain payable. As checked on September 8, 2026, the published U.S.-dollar amounts include a $125 transmittal fee, a $1,667 base international filing fee, and $19 for each sheet over thirty. The electronic-filing reduction is $251 when the request is character-coded and the application body is filed as PDF; it is $376 when the request, description, claims, and abstract meet the character-coded conditions. The search fee depends on the competent International Searching Authority selected. PCT Applicant's Guide, annex C (IB), “Fees Payable to the Receiving Office” (Aug. 31, 2026).
For an eligible electronic filing with a character-coded request, a PDF application body, no excess sheets, and no other reduction, the calculation is $125 + $1,667 − $251 = $1,541, plus the applicable search fee. Restoration adds $0 to that example's RO/IB charges. This is a dated illustration, not a complete quotation for a particular application; filing format, length, currency, search authority, and other applicable reductions can change the amount.
Professional fees are separate. Reconstructing the chronology, reviewing communications and docket records, preparing declarations, and answering an intended refusal can require substantial work. A well-supported due-care request may therefore cost more to prepare even though RO/IB charges no restoration fee. The filing decision should account for the value of the markets that a stronger restoration finding could preserve.
Later national proceedings can carry separate restoration costs when a fresh request is necessary. Recognition of an effective RO/IB grant ordinarily avoids a second restoration petition and the fee associated with that petition. In particular, entry into the U.S. national stage does not itself trigger another restoration fee when the international-stage restoration is effective there. A separately necessary U.S. petition presents a different fee event. Ordinary national-entry fees and professional charges still apply. PCT Rules r. 49ter.2(b)(iii), (d); MPEP § 1828.01; 37 C.F.R. § 1.78(b)(1)(ii), (b)(2) (2026).
A restored priority claim can receive different treatment abroad
Rule 49ter.1 governs recognition of a receiving office's restoration. A due-care restoration generally has broader effect: it is effective in designated states subject to the rule's exceptions and reservations. An unintentional restoration is effective where the applicable law uses that standard or one more favorable to applicants. Even a recognized grant remains subject to the designated-office, judicial, and other review provisions discussed below. PCT Rules r. 49ter.1(a)–(d), (g).
Rule 49ter.2 addresses a different question: whether a designated office can itself restore priority. A receiving office's refusal does not bind the designated state, but applicants should not assume that a refused request automatically becomes a national request. Availability, standard, deadline, and fees must be checked for the relevant office. PCT Rules rr. 49ter.1(e)–(f), 49ter.2.
The following comparison concerns current practice for a newly filed application. “Both” means recognition of a qualifying receiving-office decision based on either due care or unintentionality, subject to applicable review and transitional provisions. It does not mean the applicant must satisfy both standards. The country chapters are part of WIPO's PCT Applicant's Guide; national law and the applicable filing route control the ultimate result.
Office or route | Treatment of receiving-office restoration | Separate restoration after an RO/IB grant? |
United States | Both standards can be effective in the national stage. | Normally no after an effective grant. If separate local relief is needed, it uses unintentionality. MPEP § 1828.01; 37 C.F.R. § 1.78(b) (2026). |
European Patent Office | Due care is normally recognized. An unintentional-only grant is ineffective. | No after an effective due-care grant. An unintentional-only grant requires a fresh, successful due-care request to preserve priority. Eur. Pat. Off., Guidelines for Examination in the European Patent Office pt. A, ch. XV, § 5 (2026) [hereinafter EPO Guidelines]. |
United Kingdom, direct national route | Both standards can be recognized. | Normally no after a recognized grant. If separate local relief is needed, it uses unintentionality. PCT Applicant's Guide, National Chapter GB, Summary & ¶ GB.06 (Apr. 1, 2026). |
China | Both standards can be recognized under the current framework. | Normally no after a recognized grant. For a fresh request, WIPO identifies unintentionality and a period of two months from national-phase entry. PCT Applicant's Guide, National Chapter CN, Summary (Sept. 1, 2026). |
Japan | Both standards can be recognized under current rules. | Normally no after a recognized grant. Local relief uses unintentionality for priority periods expiring on or after April 1, 2023. PCT Applicant's Guide, National Chapter JP, Summary & ¶ JP.21 (July 1, 2026). |
Canada | Both standards can be recognized. | Normally no after a recognized grant. If fresh relief is needed, Canada retains a Rule 49ter.2 reservation but has domestic relief under Patent Act § 28.4(6) and Patent Rules § 77. PCT Applicant's Guide, National Chapter CA, Summary (Aug. 31, 2026). |
Australia | Both standards can be recognized. | Normally no after a recognized grant. Domestic relief includes due-care, circumstances-beyond-control, and error-or-omission grounds. PCT Applicant's Guide, National Chapter AU, Summary & ¶ AU.17 (Aug. 20, 2026). |
Germany, direct DPMA route | A Rule 49ter.1 reservation prevents reliance on the PCT recognition mechanism. | The IB grant cannot supply recognition under Rule 49ter.1. Rule 49ter.2 restoration is also unavailable at the DPMA. Consider the EPO route separately. World Intell. Prop. Org., PCT Reservations, Declarations, Notifications and Incompatibilities, entries for rr. 49ter.1(g), 49ter.2(h) (last visited Sept. 8, 2026) [hereinafter Reservations]. |
India, South Korea, and Brazil | Each maintains a Rule 49ter.1 reservation. | The IB grant does not override the reservations. Each also maintains a Rule 49ter.2 reservation, so a fresh request under that rule is unavailable. Examine any other domestic remedy separately. Reservations, entries for rr. 49ter.1(g), 49ter.2(h). |
This table illustrates why a simple list of countries that “allow restoration” can mislead. Canada's reservation concerns the PCT designated-office restoration mechanism, yet a domestic remedy remains available. Conversely, a grant by RO/IB does not neutralize another office's reservation. A reservation should prompt examination of local law rather than an unsupported assertion that every conceivable domestic remedy is foreclosed.
Historical guidance also needs care. China withdrew its relevant reservations with effect from January 20, 2024, subject to the stated transitional conditions, and Japan now uses unintentionality for the priority periods identified above. Older country charts can therefore produce the wrong strategy for a new application. Reservations, n.10; PCT Applicant's Guide, National Chapter JP, ¶ JP.21 (July 1, 2026).
After an RO/IB grant, is a separate restoration process required?
The starting point is recognition, not a mandatory second petition. If the designated office recognizes the criterion on which RO/IB restored priority, Rule 49ter.1 gives that restoration effect in the national phase, subject to its specified exceptions. The applicant ordinarily need not re-prove the same missed-deadline case through a fresh Rule 49ter.2 request. The IB decision should therefore be reviewed for its actual criterion, and its effect confirmed for each intended national or regional route. PCT Rules r. 49ter.1(a)–(d), (g).
The United States illustrates the distinction. A qualifying RO/IB restoration under either due care or unintentionality is effective in the U.S. national stage; a second petition to restore the same late filing is ordinarily unnecessary. The applicant must still satisfy the specific-reference requirements for claiming the U.S. provisional's benefit. If that reference is itself omitted or submitted late, the resulting delayed-benefit-claim issue is distinct from restoration of the missed twelve-month filing period and may require separate relief. MPEP § 1828.01; 37 C.F.R. § 1.78(b)(2), (c) (2026).
Recognition also leaves ordinary national-entry requirements in place, including applicable fees, application translations, and local representation or priority-document formalities. Compliance with those requirements is not itself a second restoration proceeding. Priority-document requirements concern the earlier application supporting the priority claim; they should not be confused with the restoration decision. Counsel should give local counsel Form PCT/RO/159 and the supporting restoration record so that the grant's scope can be checked and any permitted inquiry answered. PCT Applicant's Guide, National Phase ¶¶ 4.001, 5.009–5.010, 6.004 (Sept. 4, 2025); PCT Rules r. 51bis.1(b), (d)–(e).
A recognized restoration is not insulated from every later national inquiry. Under Rule 49ter.1(c), the restoration is ineffective in a designated state if its designated office, a court, or another competent organ finds that a specified requirement of Rule 26bis.3(a), (b)(i), or (c) was not met, taking the receiving-office reasons and evidence into account. Rule 49ter.1(d) separately limits review by the designated office: that office must reasonably doubt compliance, identify the reasons for its doubt, and permit observations within a reasonable period. Those express limits concern designated-office review; they should not be treated as a complete statement of the rules governing later judicial or other competent-organ proceedings under national law. A challenge may therefore matter during licensing or litigation as well as examination. PCT Rules r. 49ter.1(c)–(d).
A fresh national or regional request becomes important when the IB grant is ineffective in the intended route, as with an unintentional-only grant before the EPO. Such a request invokes the local office's own restoration authority and must meet its standard, deadline, reasons, evidence requirements, and any fee. The original IB request does not automatically satisfy those requirements. Where a reservation blocks both recognition and Rule 49ter.2 restoration, the applicant cannot assume that another petition will cure the problem; any domestic remedy requires separate examination. EPO Guidelines pt. A, ch. XV, § 5; PCT Applicant's Guide, National Phase ¶¶ 6.005–6.008 (Sept. 4, 2025); PCT Rules r. 49ter.2(h).
Europe shows why the actual restoration finding matters
The EPO requires due care. If RO/IB grants restoration on that basis, the EPO normally recognizes the decision, subject to the rule's review limits. If RO/IB grants restoration only because the delay was unintentional, the applicant must obtain a separate due-care restoration before the EPO to recover priority there. The EPO does not automatically treat the receiving office's refused request as its own restoration request. EPO Guidelines pt. A, ch. XV, § 5.
The ordinary EPO request deadline is one month after the thirty-one-month European-phase entry period, with a separate calculation for effective early processing and particular procedural qualifications described in the EPO Guidelines. The fresh request, statement of reasons, and restoration fee must satisfy the applicable time limit. Declarations or other evidence should preferably accompany the request; further evidence may be invited within a reasonable period. An effective RO due-care grant normally avoids this fresh request and its restoration fee, although ordinary European-phase charges remain. EPO Guidelines pt. A, ch. XV, § 5; PCT Rules r. 49ter.2(b)–(d); Implementing Regulations to the Convention on the Grant of European Patents r. 136(1).
The filing route can therefore matter as much as the country name. An unintentional-only grant may be effective on direct U.K. national entry while failing to preserve priority through the EPO. Germany presents the reverse strategic distinction: its direct national route carries a reservation, while an effective due-care restoration through the EPO may support a European patent taking effect in Germany. PCT Applicant's Guide, National Chapter GB, Summary & ¶ GB.06 (Apr. 1, 2026); Reservations, entry for r. 49ter.1(g); EPO Guidelines pt. A, ch. XV, § 5.
For the one-week-late client who considers Europe essential, a supported due-care request at RO/IB can thus have substantial practical value. If the evidence supports only unintentionality, counsel should explain that limitation at the outset and plan any available European request without implying that a later filing can repair an inadequate factual showing.
Suppose RO/IB restores the one-week-late application only under unintentionality. At U.S. national-stage entry, the applicant ordinarily relies on that grant without a second restoration petition, while satisfying the provisional-benefit reference requirements. At European-phase entry, the applicant must timely seek and obtain due-care restoration from the EPO to preserve that priority. This is a further request in the same PCT application's European phase, not a new international application. If RO/IB instead grants due-care restoration, both routes ordinarily recognize the grant without a fresh restoration request, subject to permitted review. MPEP § 1828.01; 37 C.F.R. § 1.78(b)(2) (2026); EPO Guidelines pt. A, ch. XV, § 5.
If restoration fails, the disclosure history becomes critical
The loss of priority does not necessarily eliminate every reason to file a PCT application. Protection based on the later filing date may still have value. The analysis then turns to the prior art and disclosures relevant to that later date, including publications, demonstrations, public uses, sales or offers, and third-party filings. The review must cover the period since the provisional was filed, not merely the missed week. 35 U.S.C. § 102(a).
Suppose the founder publicly demonstrated the invention six months after filing the provisional. If priority is lost, that event falls before the PCT filing date and may become material. U.S. law contains specified exceptions for certain inventor-originated disclosures within one year, but those exceptions should not be assumed to exist abroad. The European framework generally treats public disclosure before the relevant date as prior art, with narrowly defined exceptions rather than a general inventor disclosure grace period. 35 U.S.C. § 102(b)(1); Convention on the Grant of European Patents arts. 54(2), 55(1), Oct. 5, 1973, 1065 U.N.T.S. 199.
Where receiving-office restoration was omitted or refused, a fresh designated-office or domestic request may still be available. That possibility is particularly relevant in jurisdictions such as Canada and China, subject to their local requirements. It should not be confused with an unlimited extension: restoration under Rule 49ter.2 ordinarily still requires the PCT application itself to have been filed within two months after the original priority period expired. PCT Rules r. 49ter.2(a); PCT Applicant's Guide, National Chapter CA, Summary (Aug. 31, 2026); PCT Applicant's Guide, National Chapter CN, Summary (Sept. 1, 2026).
A separate U.S. filing may help, but it does not repair foreign priority
A client may also consider a U.S. nonprovisional application with a petition to restore the provisional's benefit. Section 1.78(b) permits relief when the later application's filing date falls within the additional two-month period and the delay was unintentional, subject to the petition's requirements. The petition includes the required reference, fee, and statement of unintentional delay. This domestic procedure has its own requirements; it should not be conflated with the receiving-office PCT request deadline. 37 C.F.R. § 1.78(b)(1) (2026).
That U.S. filing can form part of a coordinated strategy, but it is neither a prerequisite to filing with RO/IB nor a substitute for restoring priority where foreign protection is sought. Likewise, an international restoration does not dispense with the specific-reference requirements for claiming the provisional's benefit in the U.S. national stage. 37 C.F.R. § 1.78(b)(2) (2026).
Filing another provisional also does not automatically restart the priority year for the same invention. The Paris Convention contains a narrow rule under which a subsequent filing in the same country can replace an earlier first application, but it requires, among other things, that the earlier application have been withdrawn, abandoned, or refused without public inspection or outstanding rights and without previously serving as a priority basis. Abandonment alone is insufficient. That exception requires a separate analysis and should not be presented as a routine cure for a missed deadline. Paris Convention for the Protection of Industrial Property art. 4C(4), Mar. 20, 1883, as revised July 14, 1967, 21 U.S.T. 1583, 828 U.N.T.S. 305.
Preserve the filing opportunity and keep the later deadlines in view
Restoration does not restart the PCT timetable. When the international application is filed within the additional two-month period, the claimed priority date can continue to govern PCT procedural deadlines even if restoration is pending or ultimately unavailable. Publication and national-phase planning therefore should not be recalculated on the assumption that the missed deadline produced a fresh clock. MPEP § 1828.01; PCT Rules r. 26bis.2(c)(iii).
A later restoration request has its own clock as well. Rule 49ter.2 ordinarily measures the request period from the applicable national-entry time limit, with a separate trigger for an express early-processing request. It is not universally one month from the applicant's actual national-entry date. More favorable national provisions can change the analysis, as China's two-month period from actual entry illustrates. PCT Rules r. 49ter.2(b)(i), (f); PCT Applicant's Guide, National Chapter CN, Summary (Sept. 1, 2026). Counsel should assess any fresh-request deadline independently of an invitation to comment on the IB grant; a later inquiry should not be assumed to reopen an expired request period.
The immediate client discussion should establish the dates, the reason for the omission, the desired markets and filing routes, the disclosure history, the applicant's entitlement to priority, and the provisional's support for the intended claims. Counsel can then choose the receiving office, file the PCT application and supported restoration request within the remaining window, and respond to any intended partial refusal with the geographic consequences in mind. The file should preserve the decision's actual criterion and docket the priority-document, national-entry, and any local restoration requirements. For each intended route, local counsel should confirm whether the RO/IB grant is recognized, whether a fresh request is necessary and available, and what fee and deadline apply. That assessment should accompany national-phase planning, rather than await a notice from the designated office.
