USPTO vs EPO National Phase Entry Differences

Entering the US national stage and entering the European regional phase from the same PCT application are governed by different statutes, land on different deadlines (30 versus 31 months from priority), and demand different acts to be legally complete — so a docketing system cannot treat them as one rule with a swapped month count. This page contrasts the two head to head: the deadline, the date each period runs from, the acts that must be performed to perfect entry, and what happens when the window lapses.

Both routes descend from the same PCT National Phase Entry Rules framework, but they diverge the moment the international phase ends. Getting the divergence wrong is not a cosmetic error: a US entry docketed at 31 months is a month late, and a European entry that omits the request for examination is incomplete even if the fee posts on time.

The Core Divergence at a Glance

The US national stage is a filing under 35 U.S.C. § 371, with the requirements and time limit set by 37 CFR § 1.495. European regional entry is governed by Rule 159(1) EPC, which fixes the acts an applicant must complete to enter the regional phase before the European Patent Office. The table below is the practitioner’s cheat sheet.

Operational Action: Store the 30-month US window and the 31-month EP window as separate version-pinned rules keyed by office, never as one default with an offset — a shared “30-month” constant silently under-dockets every European family by a month.

Base Date: Both Run From Priority

The one place the two systems agree is the anchor. Both periods run from the earliest priority date claimed in the international application; where the priority claim is invalid or absent, both fall back to the international filing date under PCT Article 8. That shared anchor is exactly why the deadlines can be computed by the same National Phase Entry Date Logic primitives — only the month count and the closure calendar differ.

The month arithmetic must be calendar-correct, not a fixed day offset. Thirty months from a 15 March priority is 15 September two-and-a-half years later, and an end-of-month priority must clamp rather than spill forward. Use relativedelta:

from datetime import date
from dateutil.relativedelta import relativedelta

def entry_deadline(priority: date, months: int) -> date:
    """Priority date + N months with end-of-month clamping (Art. 22 / Art. 39).

    31 Aug 2023 + 30 months clamps to 28 Feb 2026, never spilling into March.
    """
    return priority + relativedelta(months=months)

# US national stage: 30 months. EPO regional phase: 31 months.
assert entry_deadline(date(2023, 3, 15), 30) == date(2025, 9, 15)   # USPTO
assert entry_deadline(date(2023, 3, 15), 31) == date(2025, 10, 15)  # EPO

Both offices also roll a deadline that lands on a closed day forward — the USPTO under 37 CFR § 1.7 and the EPO under Rule 134(1) EPC — but each rolls off its own closure calendar, so an identical priority date can yield deadlines that shift by different amounts.

Required Acts: Where the Routes Truly Split

The deadline difference is only one month; the acts difference is where dockets go wrong. At the USPTO, examination begins automatically once the national stage is entered — there is no separate request to file. At the EPO, the applicant must affirmatively request examination and pay the examination fee as one of the Rule 159(1) acts, and forgetting it leaves the application incomplete even though the filing and designation fees posted on time.

The EPO list is longer because the request for examination, the claims fees for claims beyond the fifteenth, and any renewal fee that has already fallen due are all folded into the entry act. A docketing model that tracks only “entry fee paid” will report a European family as safe when it is in fact incomplete. Reconciling the computed entry against the register — as the EPO Register Sync Architecture pipeline does — is what catches an entry that posted a fee but never requested examination.

Modeling Both Offices in One Rule Set

Because the two routes share an anchor but differ in month count, closure calendar, and required-act checklist, the clean model is one rule record per office with an explicit act list. Keep it in version-pinned config, cited to source:

# np_entry_offices.yaml
# Source: 37 CFR 1.495 (ecfr.gov) and Rule 159(1) EPC (epo.org/en/legal/epc/2020/r159.html)
rule_version: "2026.07.0"
offices:
  US:
    months: 30                # 30 months from priority (35 U.S.C. 371)
    closure_calendar: US
    acts: ["basic_national_fee", "search_fee", "examination_fee", "translation_en", "oath_declaration"]
    exam_request_automatic: true
  EP:
    months: 31                # 31 months from priority (Rule 159(1) EPC)
    closure_calendar: EPO
    acts: ["filing_fee", "designation_fee", "translation_en_fr_de", "request_examination", "renewal_if_due"]
    exam_request_automatic: false

A boundary validator then rejects an entry the moment a required act is missing, rather than trusting a single paid flag:

from datetime import date
from zoneinfo import ZoneInfo
from pydantic import BaseModel, field_validator

class EntryFiling(BaseModel):
    office: str                       # "US" or "EP"
    completed_acts: set[str]          # acts actually performed at entry
    filed_at: date

    @field_validator("office")
    @classmethod
    def known_office(cls, v: str) -> str:
        if v not in {"US", "EP"}:
            raise ValueError(f"Unmapped office: {v!r}")
        return v

def entry_is_complete(filing: EntryFiling, rules: dict) -> tuple[bool, set[str]]:
    """True only when every statutory act for the office was performed."""
    required = set(rules["offices"][filing.office]["acts"])
    missing = required - filing.completed_acts
    return (not missing, missing)

# Timezone for the local cutoff is resolved per office, never assumed UTC.
_OFFICE_TZ = {"US": ZoneInfo("America/New_York"), "EP": ZoneInfo("Europe/Berlin")}

Operational Action: Docket the European request for examination as its own tracked act with its own reminder, distinct from the fee payment — the single most common incomplete-entry defect is a paid filing fee with no examination request on file.

Consequences of Missing the Deadline

The failure modes are asymmetric. Miss the US 30-month deadline and the application goes abandoned; it can be revived under 37 CFR § 1.137 on a showing that the entire delay was unintentional, with a petition and fee — a remedy examined in depth in Recovering a Missed PCT National Phase Entry via USPTO Restoration Petition. Miss the European 31-month deadline and the application is deemed withdrawn under Rule 160(1) EPC; the standard cure is further processing under Rule 135 EPC, a no-fault remedy on request plus fee, contrasted with the stricter re-establishment path in EPO Further Processing vs Re-establishment of Rights.

The docketing consequence is that the two systems need different escalation logic. A missed US entry raises an “unintentional-delay revival” flag; a missed EP entry raises a “further-processing window open” flag with its own short deadline. Encoding both as a generic “missed — escalate” event loses the information counsel needs to act.

Frequently Asked Questions

Related

• PCT National Phase Entry Rules — the deterministic engine that computes both windows from one priority anchor.
• PCT Chapter I vs Chapter II National Phase Timing — how the demand path affects the 30/31-month choice.
• EPO Further Processing vs Re-establishment of Rights — the European remedy when regional entry is missed.
• National Phase Entry Date Logic — the shared date-arithmetic primitives both routes depend on.

↑ Back to PCT National Phase Entry Rules