# MPEP § 502: Depositing Correspondence

> Federal · Agency guidance · In force

URL: https://www.frixlaw.com/law-library/statutes/MPEP_S502

## Section

- **Citation:** MPEP § 502
- **Heading:** Depositing Correspondence
- **Jurisdiction:** Federal
- **Kind:** Agency guidance
- **Status:** In force
- **Text as of:** August 14, 2026
- **Source:** Compiled text
- **Location:** USPTO MPEP / Chapter 0500 - Receipt and Handling of Mail and Papers / MPEP § 502

## Text

37 CFR 1.5  Identification of patent, patent application, or patent-related
proceeding.
(a) No correspondence relating to an application should be filed prior
to receipt of the assigned application number (i.e., U.S. application number,
international application number, or international registration number as
appropriate). When correspondence directed to the Patent and Trademark Office
concerns a previously filed application for a patent, it must identify on the top
page in a conspicuous location, the application number (consisting of the series
code and the serial number; e.g., 07/123,456), or the serial number and filing
date assigned to that application by the Patent and Trademark Office, or the
international application number of the international application, or the
international registration number of an international design application. Any
correspondence not containing such identification will be returned to the sender
where a return address is available. The returned correspondence will be
accompanied with a cover letter which will indicate to the sender that if the
returned correspondence is resubmitted to the Patent and Trademark Office within
two weeks of the mail date on the cover letter, the original date of receipt of
the correspondence will be considered by the Patent and Trademark Office as the
date of receipt of the correspondence. Applicants may use either the Certificate
of Mailing or Transmission procedure under
§ 1.8
or the Priority Mail
Express
®
procedure under
§ 1.10
for
resubmissions of returned correspondence if they desire to have the benefit of the
date of deposit in the United States Postal Service. If the returned
correspondence is not resubmitted within the two-week period, the date of receipt
of the resubmission will be considered to be the date of receipt of the
correspondence. The two-week period to resubmit the returned correspondence will
not be extended
submissions of returned correspondence if they desire to have the benefit of the
date of deposit in the United States Postal Service. If the returned
correspondence is not resubmitted within the two-week period, the date of receipt
of the resubmission will be considered to be the date of receipt of the
correspondence. The two-week period to resubmit the returned correspondence will
not be extended. In addition to the application number, all correspondence
directed to the Patent and Trademark Office concerning applications for patent
should also state the name of the first listed inventor, the title of the
invention, the date of filing the same, and if known, the group art unit or other
unit within the Patent and Trademark Office responsible for considering the
correspondence and the name of the examiner or other person to which it has been
assigned.
(b) When the letter concerns a patent other than for purposes of
paying a maintenance fee, it should state the number and date of issue of the
patent, the name of the patentee, and the title of the invention. For letters
concerning payment of a maintenance fee in a patent, see the provisions of
§
1.366(c)
.
(c) Correspondence relating to a trial proceeding before the Patent
Trial and Appeal Board (part 42 of this title) are governed by
§
42.6
of this title.
(d) A letter relating to a reexamination or supplemental examination
proceeding should identify it as such by the number of the patent undergoing
reexamination or supplemental examination, the request control number assigned to
such proceeding, and, if known, the group art unit and name of the examiner to
which it been assigned.
(e) [Reserved]
(f) When a paper concerns a provisional application, it should
identify the application as such and include the application number.
37 CFR 1.6  Receipt of correspondence.
mber of the patent undergoing
reexamination or supplemental examination, the request control number assigned to
such proceeding, and, if known, the group art unit and name of the examiner to
which it been assigned.
(e) [Reserved]
(f) When a paper concerns a provisional application, it should
identify the application as such and include the application number.
37 CFR 1.6  Receipt of correspondence.
(a)
Date of receipt and Priority Mail Express
®
date of deposit.
Correspondence received in the Patent and Trademark
Office is stamped with the date of receipt except as follows:
(1) The Patent and Trademark Office is not open for the filing
of correspondence on any day that is a Saturday, Sunday, or Federal holiday
within the District of Columbia. Except for correspondence transmitted by
facsimile under paragraph (a)(3) of this section, or filed electronically
under paragraph (a)(4) of this section, no correspondence is received in the
Office on Saturdays, Sundays, or Federal holidays within the District of
Columbia.
(2) Correspondence filed in accordance with
§ 1.10
will be stamped with the date of deposit as Priority Mail
Express
®
with the United States Postal
Service.
(3) Correspondence transmitted by facsimile to the Patent and
Trademark Office will be stamped with the date on which the complete
transmission is received in the Patent and Trademark Office unless that date
is a Saturday, Sunday, or Federal holiday within the District of Columbia,
in which case the date stamped will be the next succeeding day which is not
a Saturday, Sunday, or Federal holiday within the District of Columbia.
by facsimile to the Patent and
Trademark Office will be stamped with the date on which the complete
transmission is received in the Patent and Trademark Office unless that date
is a Saturday, Sunday, or Federal holiday within the District of Columbia,
in which case the date stamped will be the next succeeding day which is not
a Saturday, Sunday, or Federal holiday within the District of Columbia.
(4) Correspondence may be submitted using the USPTO patent
electronic filing system only in accordance with the USPTO patent electronic
filing system requirements. Correspondence officially submitted to the
Office by way of the USPTO patent electronic filing system will be accorded
a receipt date, which is the date in Eastern Time when the correspondence is
received in the Office, regardless of whether that date is a Saturday,
Sunday, or Federal holiday within the District of Columbia.
(b) [Reserved]
(c)
Correspondence delivered by hand.
In addition to being mailed,
correspondence may be delivered by hand during hours the Office is open to receive
correspondence.
(d)
Facsimile transmission.
Except in the cases enumerated below,
correspondence, including authorizations to charge a deposit account, may be
transmitted by facsimile. The receipt date accorded to the correspondence will be
the date on which the complete transmission is received in the United States
Patent and Trademark Office, unless that date is a Saturday, Sunday, or Federal
holiday within the District of Columbia. See paragraph (a)(3) of this section. To
facilitate proper processing, each transmission session should be limited to
correspondence to be filed in a single application or other proceeding before the
United States Patent and Trademark Office
sion is received in the United States
Patent and Trademark Office, unless that date is a Saturday, Sunday, or Federal
holiday within the District of Columbia. See paragraph (a)(3) of this section. To
facilitate proper processing, each transmission session should be limited to
correspondence to be filed in a single application or other proceeding before the
United States Patent and Trademark Office. The application number of a patent
application, the control number of a reexamination or supplemental examination
proceeding, the interference number of an interference proceeding, the trial
number of a trial proceeding before the Board, or the patent number of a patent
should be entered as a part of the sender's identification on a facsimile cover
sheet. Facsimile transmissions are not permitted and, if submitted, will not be
accorded a date of receipt in the following situations:
(1) [Reserved];
(2) Certified documents as specified in
§ 1.4(f)
;
(3) Correspondence that cannot receive the benefit of the
certificate of mailing or transmission as specified in
§ 1.8(a)(2)(i)(A) through
(D),(F), (I), and (K)
, and
§ 1.8(a)(2)(iii)(A)
, except that a continued
prosecution application under
§ 1.53(d)
may be
transmitted to the Office by facsimile;
(4) Color drawings submitted under
§§
1.81
,
1.83
through
1.85
,
1.152
,
1.165
,
1.173
,
1.437
, or
1.1026
;
(5) A request for reexamination under
§ 1.510
or
§ 1.913
, or a request
for supplemental examination under
§
1.610
;
(6) Correspondence to be filed in an application subject to a
secrecy order under
§§ 5.1
through
5.5
of this chapter and directly related to the
secrecy order content of the application;
(7) In contested cases and trials before the Patent Trial and
Appeal Board, except as the Board may expressly authorize.
(e) [Reserved]
1.510
or
§ 1.913
, or a request
for supplemental examination under
§
1.610
;
(6) Correspondence to be filed in an application subject to a
secrecy order under
§§ 5.1
through
5.5
of this chapter and directly related to the
secrecy order content of the application;
(7) In contested cases and trials before the Patent Trial and
Appeal Board, except as the Board may expressly authorize.
(e) [Reserved]
(f)
Facsimile transmission of a patent application under
§ 1.53(d)
.
In the event that the Office has no
evidence of receipt of an application under
§ 1.53(d)
(a continued
prosecution application) transmitted to the Office by facsimile transmission, the
party who transmitted the application under
§ 1.53(d)
may petition the
Director to accord the application under
§ 1.53(d)
a filing date as of
the date the application under
§ 1.53(d)
is shown to have
been transmitted to and received in the Office,
(1) Provided that the party who transmitted such application
under
§
1.53(d)
:
(i) Informs the Office of the previous transmission of the
application under
§ 1.53(d)
promptly
after becoming aware that the Office has no evidence of receipt of the
application under
§ 1.53(d)
;
(ii) Supplies an additional copy of the previously
transmitted application under
§ 1.53(d)
; and
(iii) Includes a statement which attests on a personal
knowledge basis or to the satisfaction of the Director to the previous
transmission of the application under
§ 1.53(d)
and is accompanied by a copy of the
sending unit’s report confirming transmission of the application under
§
1.53(d)
or evidence that came into being after
the complete transmission and within one business day of the complete
transmission of the application under
§ 1.53(d)
.
(2) The Office may require additional evidence to determine if
the application under
§ 1.53(d)
was
transmitted to and received in the Office on the date in question.
ng unit’s report confirming transmission of the application under
§
1.53(d)
or evidence that came into being after
the complete transmission and within one business day of the complete
transmission of the application under
§ 1.53(d)
.
(2) The Office may require additional evidence to determine if
the application under
§ 1.53(d)
was
transmitted to and received in the Office on the date in question.
(g)
Submission of the national stage correspondence required by
§
1.495
via the USPTO patent electronic filing
system.
In the event that the Office has no evidence of receipt of
the national stage correspondence required by
§ 1.495
, which was submitted
to the Office by the USPTO patent electronic filing system, the party who
submitted the correspondence may petition the Director to accord the national
stage correspondence a receipt date as of the date the correspondence is shown to
have been officially submitted to the Office.
(1) The petition of this paragraph (g) requires that the party
who submitted such national stage correspondence:
(i) Informs the Office of the previous submission of the
correspondence promptly after becoming aware that the Office has no
evidence of receipt of the correspondence under
§
1.495
;
(ii) Supplies an additional copy of the previously
submitted correspondence;
(iii) Includes a statement that attests on a personal
knowledge basis, or to the satisfaction of the Director, that the
correspondence was previously officially submitted; and
(iv) Supplies a copy of an acknowledgment receipt generated
by the USPTO patent electronic filing system, or equivalent evidence,
confirming the submission to support the statement of paragraph
usly
submitted correspondence;
(iii) Includes a statement that attests on a personal
knowledge basis, or to the satisfaction of the Director, that the
correspondence was previously officially submitted; and
(iv) Supplies a copy of an acknowledgment receipt generated
by the USPTO patent electronic filing system, or equivalent evidence,
confirming the submission to support the statement of paragraph
(g)(1)(iii) of this section.
(2) The Office may require additional evidence to determine if
the national stage correspondence was submitted to the Office on the date in
question.
All applications (provisional and nonprovisional) may be sent to the U.S.
Patent and Trademark Office by mail using the United States Postal Service (see
MPEP §
501
), or they may be hand-carried to the Customer Service Window
in Alexandria, Virginia. However, applicants should consider filing new patent applications
(as well as patent-related correspondence) via the USPTO patent electronic filing system
whenever permitted. See the USPTO Online Filing webpage for additional information on the
USPTO patent electronic filing system (
www.uspto.gov/patents/apply
).
See also
MPEP §
502.05
. New applications
cannot
be transmitted by
facsimile and are
not
entitled to the benefit of a Certificate of Transmission
under
37 CFR
1.8
. A request for a continued prosecution application (CPA) filed
under
37 CFR
1.53(d)
(available only for design applications) may be transmitted
to the Office by facsimile (
37 CFR 1.6(d)(3)
); however, it is not
entitled to the benefit of a Certificate of Transmission (see
37 CFR
1.8(a)(2)(i)(A)
). See
37 CFR 1.6(d)
and
MPEP § 502.01
.
See 37 CFR 2.190 and
MPEP § 501
for addresses pertaining to
trademark correspondence.
All correspondence related to a national patent application already filed
with the U.S. Patent and Trademark Office must include the identification of the
application number or the serial number and the filing date assigned to the application by
the Office
1.8(a)(2)(i)(A)
). See
37 CFR 1.6(d)
and
MPEP § 502.01
.
See 37 CFR 2.190 and
MPEP § 501
for addresses pertaining to
trademark correspondence.
All correspondence related to a national patent application already filed
with the U.S. Patent and Trademark Office must include the identification of the
application number or the serial number and the filing date assigned to the application by
the Office. Any correspondence not containing the proper identification set forth in
37 CFR
1.5(a)
will be returned to the sender by the Office of Patent
Application Processing (OPAP). Each paper should be inspected to assure that the papers
being returned contain an “Office Date” stamp indicating the date of receipt. If there is a
minor obvious error in the identification of the application such that the Office readily
recognizes both the existence of the error and the appropriate correction, the error can be
corrected by the Office. The Office often experiences difficulty in matching incoming
papers with the application file to which they pertain because insufficient or erroneous
information is given. This applies especially to amendments, powers of attorney, changes of
address, status letters, petitions for extension of time, and other petitions.
It would be of great assistance to the Office if
all
incoming papers pertaining to a filed application carried the following items:
(A) Application number (checked for accuracy, including series code and
serial no.).
(B) Art Unit number (copied from most recent Office communication).
(C) Filing date.
(D) Name of the examiner who prepared the most recent Office action.
(E) Title of invention.
(F) Confirmation number (see
MPEP §
503
).
Applicants may be reminded of this by including form paragraph 5.01.

## Nearby sections

- [MPEP § 501 Filing Papers With the U.S. Patent and Trademark Office](https://www.frixlaw.com/law-library/statutes/MPEP_S501.md)
- [MPEP § 502 Depositing Correspondence](https://www.frixlaw.com/law-library/statutes/MPEP_S502.md)
- [MPEP § 502.01 Correspondence Transmitted by Facsimile](https://www.frixlaw.com/law-library/statutes/MPEP_S502.01.md)
- [MPEP § 502.02 Correspondence Signature Requirements](https://www.frixlaw.com/law-library/statutes/MPEP_S502.02.md)
- [MPEP § 502.03 Communications via Internet Electronic Mail (email)](https://www.frixlaw.com/law-library/statutes/MPEP_S502.03.md)
- [MPEP § 502.04 Duplicate Copies of Correspondence](https://www.frixlaw.com/law-library/statutes/MPEP_S502.04.md)
- [MPEP § 502.05 Correspondence Transmitted by EFS-Web](https://www.frixlaw.com/law-library/statutes/MPEP_S502.05.md)
- [MPEP § 503 Application Number and Filing Receipt](https://www.frixlaw.com/law-library/statutes/MPEP_S503.md)
- [MPEP § 504 Assignment of Application for Examination](https://www.frixlaw.com/law-library/statutes/MPEP_S504.md)
- [MPEP § 505 Date of Receipt Stamp](https://www.frixlaw.com/law-library/statutes/MPEP_S505.md)
- [MPEP § 506 Completeness of Original Application](https://www.frixlaw.com/law-library/statutes/MPEP_S506.md)
- [MPEP § 506.01 [Reserved]](https://www.frixlaw.com/law-library/statutes/MPEP_S506.01.md)
- [MPEP § 506.02 Review of Refusal To Accord Filing Date](https://www.frixlaw.com/law-library/statutes/MPEP_S506.02.md)
- [MPEP § 507 Drawing Review in the Office of Patent Application Processing](https://www.frixlaw.com/law-library/statutes/MPEP_S507.md)

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Source: Frix Law Library, https://www.frixlaw.com/law-library/statutes/MPEP_S502. Check the current official text before relying on it. Not legal advice.