503 Application Number and Filing Receipt [R-07.2022]

37 CFR 1.54  Parts of application to be filed together; filing receipt.

  • (a) It is desirable that all parts of the complete application be deposited in the Office together; otherwise, a letter must accompany each part, accurately and clearly connecting it with the other parts of the application. See § 1.53(f) and (g) with regard to completion of an application.
  • (b) Applicant will be informed of the application number and filing date by a filing receipt, unless the application is an application filed under § 1.53(d). A letter limited to a request for a filing receipt may be signed by a juristic applicant or patent owner.


Application numbers consisting of a series code and a serial number are assigned by the Office of Patent Application Processing (OPAP) immediately after mail has been opened. If an application is filed using the USPTO patent electronic filing system, EFS-Web provides an Acknowledgement Receipt that contains a time and date stamp, an application number and a confirmation number.

The following series codes are assigned to the applications identified below:

  • (A) 01/ – 16/ – for nonprovisional applications (utility, plant, and reissue), during the following time periods:
    • 01 –1925 to 1934,
    • 02 – 1935 to 1947,
    • 03 – 1948 to 1959,
    • 04 – 1960 to 1969,
    • 05 – 1970 to 1978,
    • 06 – 1979 to 1986,
    • 07 – 1987 to 1992,
    • 08 – 1993 to 1997,
    • 09 – 1998 to Nov. 2001,
    • 10 – Dec. 2001 to Nov. 2004,
    • 11 – Dec. 2004 to Dec. 2007,
    • 12 – Dec. 2007 to Mar. 2011,
    • 13 – Dec. 2010 to Aug. 2013,
    • 14 – Aug. 2013 to July 2016,
    • 15 – Jan. 2016 to June 2018, and
    • 16 – June 2018 to present.
  • (B) 29/ – for design applications;
  • (C) 35/ – for international design applications;
  • (D) 60/, 61/, and 62/ – for provisional applications;
  • (E) 90/ – for ex parte reexamination proceedings;
  • (F) 95/ – for inter partes reexamination proceedings; and
  • (G) 96/ – for supplemental examination proceedings and resulting ex parte reexamination proceedings.

If a self-addressed postcard is submitted with a patent application, that postcard will be provided with both the receipt date and application number prior to returning it to the addressee. The application number identified on such a postcard receipt is merely the preliminary assignment of an application number to the application, and should not be relied upon (e.g., with respect to foreign filings) as necessarily representing the application number assigned to such application. See 37 CFR 1.53(b).

The identifying data on the postcard should include:

  • (A) inventor’s name(s);
  • (B) title of invention;
  • (C) number of pages of specification, claims (for nonprovisional applications), and sheets of drawing;
  • (D) whether the inventor’s oath or declaration is included;
  • (E) a list of any additional forms included with the application (e.g., application transmittal form, application data sheet, fee transmittal form, and/or provisional application cover sheet); and
  • (F) amount and manner of paying the fee.

A return postcard should be attached to each patent application for which a receipt is desired.

It is important that the return postcard itemize all of the components of the application. If the postcard does not itemize each of the components of the application, it will not serve as evidence that any component which was not itemized was received by the United States Patent and Trademark Office (USPTO). See subsection III, below, for additional information pertaining to return postcards. It should be recognized that the identification of an application by application number does not necessarily signify that the USPTO has accepted the application as complete (37 CFR 1.53(a)).

For applications filed via EFS-Web and Patent Center, after the Office receives a successful submission, an Electronic Acknowledgement Receipt is sent to the person filing the application. The acknowledgment receipt contains the “receipt date,” the time the correspondence was received at the Office (not the local time at the submitter’s location), and a full listing of the correspondence submitted. The Electronic Acknowledgement Receipt is the electronic equivalent of a postcard receipt. See MPEP § 502.05.


OPAP mails a filing receipt to the attorney or agent, if any, otherwise to the applicant, at the correspondence address of record for each application filed which meets the minimum requirements to receive a filing date. The filing receipt includes the application number, filing date, a confirmation number, a suggested class in the U.S. Patent Classification System (see MPEP § 902.01), and the number of an art unit where the application is likely to be examined. The filing receipt also includes other information about the application as applicable, such as continuing data, national stage data, foreign priority data, foreign filing license data, entity status information, and the date the Office anticipates publishing the application under 35 U.S.C. 122(b). The filing receipt represents the official assignment by the USPTO of a specific application number and confirmation number to a particular application. See 37 CFR 1.54(b). The application number officially assigned to an application on the filing receipt may differ from the application number identified on a postcard receipt submitted with such application, and, as between inconsistent filing receipts and postcard receipts, the application number on the filing receipt is controlling.

Applicants are encouraged to check their filing receipts for accuracy with particular attention to the inventor’s and applicant’s names, benefit and priority claims, and whether or not a nonpublication request, if submitted, was recognized .

The confirmation number is a four-digit number that is assigned to each newly filed application. The confirmation number, in combination with the application number, is used to verify the accuracy of the application number placed on correspondence filed with the Office to avoid misidentification of an application due to a transposition error in the application number. The confirmation number may be found in the upper left-hand corner of the filing receipt. The confirmation number will also be available through the Patent Application Information Retrieval (PAIR) system. The Office includes the application’s confirmation number (in addition to the application number) on the cover sheet accompanying Office actions and on filing receipts. The confirmation number must be used when submitting an electronic filing system (EFS-Web or Patent Center) copy of the application for publication to verify that the application number correctly identifies the application for which a copy is being submitted for publication. The Office also recommends that applicants include the application’s confirmation number (in addition to the application number) on all correspondence submitted to the Office concerning the application.

A continued prosecution application (CPA) filed under 37 CFR 1.53(d) (design applications only) will be assigned the application number of the prior application for identification purposes.

A nonprovisional application, other than a CPA filed under 37 CFR 1.53(d), is entitled to a filing date as of the date of receipt of the specification, including claims, and any required drawing. See 37 CFR 1.53(b). The filing receipt will be mailed at the time a determination is made that the application meets the minimum requirements to receive a filing date. The inventor’s oath or declaration, basic filing fee, and search fee and examination fee as set forth in 37 CFR 1.16, may be filed later than the remaining application papers, but if so, they must be accompanied by the required surcharge (if appropriate, see MPEP § 506). See 37 CFR 1.53(f). If the inventor’s oath or declaration, basic filing fee, and/or any required search fee and examination fee with the appropriate surcharge are not timely filed, the application will be abandoned. For original (non-reissue) applications filed on or after September 16, 2012, the filing of the inventor’s oath or declaration may be postponed until the date the issue fee is paid if an application data sheet in accordance with 37 CFR 1.76 is timely filed providing the required inventor information. See 35 U.S.C. 115(f) and 37 CFR 1.53(f). The surcharge required for filing the inventor’s oath or declaration after the filing date of the application, however, must be paid on filing of the application or in response to a Notice to File Missing Parts. Also, for applications filed on or after December 18, 2013, the filing of at least one claim may be postponed until the expiration of the time period set in Notice to File Missing Parts. Claim(s) and the surcharge must be filed in response to the Notice to File Missing Parts. See MPEP § 506.

A provisional application filed on or after December 18, 2013 is entitled to a filing date as of the date of receipt of the specification, with or without claims, in the Office (37 CFR 1.53(c)); a provisional application filed before December 18, 2013 must also include any required drawings to be entitled to a filing date (pre-PLT (AIA) 37 CFR 1.53 (c)). See also MPEP § 608.02, subsection I. See 37 CFR 1.53(c). A cover sheet (37 CFR 1.51(c)(1)), which may be an application data sheet (37 CFR 1.76) or a cover letter, identifying the application as a provisional application is required to prevent the provisional application from being treated as a nonprovisional application. 37 CFR 1.53(c)(1).

Each application which meets the minimum requirements to receive a filing date is given a filing date. It is important, when referring to application files, to identify them by their filing dates and confirmation numbers as well as by application numbers.

Attorney docket numbers must be limited to a maximum of 25 characters to prevent truncation. The USPTO system data base allows a maximum of 25 characters for the attorney docket numbers. Spaces, slashes, and hyphens will no longer be included in the entered docket number on the official filing receipt. In an application where CASE or NAVY-CASE appears before the first character in the docket number, only the characters after CASE or NAVY-CASE will be entered on the official filing receipt.

The application papers are processed by OPAP and added to the Office’s Image File Wrapper (IFW) system.

Applications which are entitled to a filing date, whether filed by regular mail, by Priority Mail Express® under 37 CFR 1.10, by hand-delivery, by the USPTO patent electronic filing system, or otherwise, will not be returned to applicant even if requested. See 37 CFR 1.59. Accordingly, applicants must be careful not to file applications which are not intended to be filed, e.g., duplicates of applications already filed. Note that 37 CFR 1.26(a) provides that a change of purpose after the payment of a fee, as when a party desires to withdraw the filing of a patent application for which the fee was paid, will not entitle the party to a refund of such fee. See MPEP § 607.02.


If a submitter desires a receipt for any item (e.g., paper or fee) filed in the USPTO by means other than the USPTO patent electronic filing system, it may be obtained by enclosing with the paper a self-addressed postcard specifically identifying the item. See subsection I, above, and MPEP § 502.05 for Electronic Acknowledgment Receipts. To ensure the receipt of return receipt postcards, users must either: (A) purchase already stamped postcards from the United States Postal Service (USPS) or affix postage stamps to their postcards; or (B) if a postage meter is used, ensure that the meter postmark does not show the date. Any return receipt postcard containing a dated meter postmark may not be delivered by the USPS to the address provided on the postcard. Users are reminded that they are solely responsible for placing the proper postage on self-addressed postcards that are submitted to the USPTO for the purpose of obtaining a receipt for correspondence being filed in the USPTO. Users should check with the USPS regarding postage and what size cards are acceptable to the USPS. Any return receipt postcard that does not contain sufficient postage or is not acceptable may not be delivered by the USPS to the address provided on the postcard, and, if returned to the USPTO, may be discarded.

The USPTO will stamp the receipt date on the postcard and place it in the outgoing mail. A postcard receipt which itemizes and properly identifies the items which are being filed serves as prima facie evidence of receipt in the USPTO of all the items listed thereon on the date stamped thereon by the USPTO.

The identifying data on the postcard should be so complete as to clearly identify the item for which a receipt is requested. For example, the postcard should identify the inventor’s name, application number (if known), confirmation number (if known), filing date, interference number, title of the invention, etc. The postcard should also identify the type of paper being filed, e.g., new application, affidavit, amendment, notice of appeal, appeal brief, drawings, fees, motions, supplemental oath or declaration, petition, etc., and the number of pages being submitted. If a new application is being filed, all parts of the application being submitted should be separately listed on the postcard, e.g., the number of pages of specification (including written description, claims and abstract), number of claims, number of sheets of drawings, number of pages of oath/declaration, number of pages of cover sheet (provisional application).

The postcard receipt will not serve as prima facie evidence of receipt of any item which is not adequately itemized on the postcard. For example, merely listing on the postcard “a complete application” or “patent application” will not serve as a proper receipt for each of the required components of an application (e.g., specification (including claims), drawings (if necessary), oath or declaration and the application filing fee) or missing portions (e.g., pages, sheets of drawings) of an application if one of the components or portion of a component is found to be missing by the USPTO. Each separate component should be specifically and properly itemized on the postcard. Furthermore, merely incorporating by reference in the postcard receipt, the items listed in a transmittal letter will not serve as prima facie evidence of receipt of those items.

The person receiving the item(s) in the USPTO will check the listing on the postcard against the item(s) being filed to be sure they are properly identified and that all the items listed on the postcard are presently being submitted to the USPTO. If any of the items listed on the postcard are not being submitted to the USPTO, those items will be crossed off and the postcard initialed by the person receiving the items.

Upon return of a postcard receipt from the USPTO, the postcard receipt should be promptly reviewed by the person who filed the items to ensure that every item specifically denoted on the postcard was received by the USPTO. If the postcard receipt has been annotated to indicate that a particular item denoted on the postcard was not received by the USPTO, the postcard receipt will not serve as prima facie evidence of receipt of that item in the USPTO.