# FIM
> Source: https://docs.barcoder.ai/docs/standards/fim
> research date 2026-10-03 · extracted at 2026-10-03
> Publisher: Barcoder — encyclopedia of QR, barcode and payment-code standards
Specifications:
- [USPS Publication 25 — Chapter 10: Facing Identification Mark (FIM)](https://about.usps.com/publications/pub25/pub25_ch10_toc.htm)
- [Postal Bulletin 22285 — DMM Revision: New Facing Identification Mark E Pattern (DMM 708.9)](https://about.usps.com/postal-bulletin/2010/pb22285/html/updt_003.htm)
## Overview
The **Facing Identification Mark** (**FIM**) is a pattern of vertical bars printed in the upper-right portion of a letter-size mailpiece, to the left of the postage area, defined by the **United States Postal Service** [1][1], [10][10]. It allows automatic **facing** (orientation) of letter mail for cancellation and identifies reply mail that carries a preprinted barcode so that equipment can route it directly to high-speed barcode sorters [10][10]. A FIM is "essentially a nine-bit code consisting of bars and no-bar placeholders"; five patterns, **FIM A** through **FIM E**, are defined [3][3], [1][1].
## History
- The FIM was designed by the USPS to assist automated processing of mail, letting letters be faced correctly for cancellation [1][1], [6][6].
- Patterns A–D were originally assigned to courtesy/meter reply mail (A), Business Reply Mail without a preprinted ZIP+4 barcode (B), Business Reply Mail with a preprinted ZIP+4 barcode (C), and information-based indicia (IBI) postage (D) [4][4], [5][5]. Early references describe the barcode on reply mail as a [POSTNET](https://docs.barcoder.ai/docs/standards/postnet) ZIP+4 barcode [6][6].
- **Effective June 7, 2010**, the USPS revised Domestic Mail Manual (DMM) section **708.9.2** to add a fifth pattern, **FIM E** (`101000101`), for postcard- and letter-size First-Class Mail with customized services, limited to pre-approved customers in specific USPS programs [4][4]. The test pieces combined FIM E with an [Intelligent Mail Barcode](https://docs.barcoder.ai/docs/standards/intelligent-mail-barcode) and a "No Postage Necessary If Mailed in the United States" legend in place of postage [4][4].
No fetched source gives the year the FIM was first introduced; it is omitted here.
## Technical specification
The FIM is a **fixed-pattern, non-data-bearing** 1D bar mark: it carries no variable payload, only one of five predefined patterns [6][6], [3][3]. Each of the nine positions is either a bar (`1`) or an empty placeholder (`0`) [3][3].
| Pattern | Binary code | Bars | Assigned use (Publication 25) |
|---|---|---|---|
| FIM A | `110010011` | 5 | Courtesy Reply Mail and metered reply mail with a preprinted barcode |
| FIM B | `101101101` | 6 | Business Reply Mail, no preprinted barcode |
| FIM C | `110101011` | 6 | Business Reply Mail / Permit Reply Mail with a preprinted barcode |
| FIM D | `111010111` | 7 | PC Postage / IBI postage (printed in nonfluorescent ink directly on the envelope) |
| FIM E | `101000101` | 4 | First-Class postcards and letters with customized services and an Intelligent Mail barcode |
Codes and uses per [3][3]; bar counts are the number of `1` positions in each code. Seagull Scientific confirms five bars for FIM A and six for FIM C [6][6].
**Structural rules** — every pattern starts and ends with a bar, is palindromic (reads the same in either direction), and never has more than three consecutive bars or spaces [1][1].
**Physical dimensions and placement** [5][5], [6][6]:
| Parameter | Value |
|---|---|
| Bar height | 5/8 in ± 1/8 in (0.625 in) |
| Bar width | 1/32 in ± 0.008 in (0.03125 in) |
| Overall width | 0.53125 in |
| Horizontal position | rightmost bar 2 in ± 1/8 in from the right edge of the mailpiece |
| Vertical position | top of bars no lower than 1/8 in from the top edge (may extend over the flap) |
| Clear zone | no other printing; spans 3 in to 1.75 in from the right edge, 0.625 in down from the top; bar bottoms touch the clear-zone boundary within 1/8 in |
There is no check digit or error correction: the mark identifies a mail category, it does not encode data [6][6].
## Use cases
Publication 25 makes the FIM mandatory on specific letter-size mail and forbids it elsewhere [2][2]:
- **Business Reply Mail (BRM)** — FIM B or FIM C [2][2].
- **Permit Reply Mail (PRM)** — FIM C [2][2].
- **Courtesy Reply Mail (CRM) and metered reply mail** — FIM A [2][2].
- **IBI meter mail / PC Postage** — FIM D [2][2], [3][3].
- **Absentee balloting materials** — FIM C [2][2].
- **Customized-service First-Class postcards** — FIM E, for pre-approved mailers ("Share Mail" in Wikipedia's description) [4][4], [1][1].
Mailers may not use a FIM on other mail, except a letter-size permit-imprint envelope designed as a reusable mailpiece [2][2]. On the processing side, FIM E is described as orienting, separating, and capturing mailpiece images on the USPS **Advanced Facer Canceler System (AFCS)** [4][4], and Publication 25 states that the FIM serves "to orient and separate certain types of First-Class Mail pieces during the facing-canceling process" [2][2].
## Implementations
- **JavaScript** — [metafloor/bwip-js][7] — ~2.4k★, release 4.11.4 (2026-08-19). Port of Barcode Writer in Pure PostScript (BWIPP); FIMs are rendered with the `symbol` encoder and data values `fima`, `fimb`, `fimc`, `fimd` [7][7], [8][8]. (bwip-js in the Barcoder environment also accepted `fime` during verification, but BWIPP's wiki documents only A–D.)
- **C** — [zint/zint][9] — 810★, BSD-3 library with GPL CLI/GUI; exposes FIM as symbology `BARCODE_FIM`, surfaced in the ruby-zint bindings as `Zint::Fim` [9][9].
- **Commercial** — Neodynamic's barcode SDKs (.NET, WPF, ThermalLabel) include a FIM symbology enum covering A–D [5][5].
- **Decoders** — no open-source FIM decoder was found. As a fixed pattern-matching mark, reading is done inside USPS facer-canceler equipment [2][2], [4][4].
## Comparison
**vs. [POSTNET](https://docs.barcoder.ai/docs/standards/postnet) and [Intelligent Mail Barcode](https://docs.barcoder.ai/docs/standards/intelligent-mail-barcode)** — POSTNET and the IMb are height-modulated symbologies that carry variable routing (and, for the IMb, tracking) data with check digits or a CRC; the FIM carries no data and uses full-height bars at fixed positions to signal *mail category and orientation* [6][6], [3][3]. The two are complementary: FIM A and FIM C announce that a preprinted barcode (historically POSTNET, today the IMb) is present, so the piece can bypass optical character reading and go straight to barcode sorting [10][10], [6][6], [3][3].
**vs. [PLANET](https://docs.barcoder.ai/docs/standards/planet)** — PLANET encoded tracking numbers for USPS Confirm; the FIM never identifies an individual piece [6][6].
**When to use** — print a FIM only when the DMM requires it for the reply/IBI mail categories above; pick the pattern by mail type and whether a barcode is preprinted [2][2], [3][3].
## Fun facts
- All five FIM patterns are **palindromes**, so they read identically whichever way a letter travels through the facer [1][1].
- FIM D for PC Postage is printed in **nonfluorescent ink** directly on the envelope, unlike conventionally tagged stamps that facer-cancelers detect by phosphorescence [3][3], [1][1].
## Status
**Active.** The FIM remains defined in USPS Publication 25 (Chapter 10) and DMM 708.9, with five patterns in use; Wikipedia's article (updated January 2026) lists FIM A–E as current, with FIM A and FIM C now referencing the Intelligent Mail barcode [1][1], [2][2], [3][3]. No successor has been announced.
## Sources
[1]: https://en.wikipedia.org/wiki/Facing_Identification_Mark
[2]: https://about.usps.com/publications/pub25/pub25_ch10_002.htm
[3]: https://about.usps.com/publications/pub25/pub25_ch10_003.htm
[4]: https://about.usps.com/postal-bulletin/2010/pb22285/html/updt_003.htm
[5]: https://www.neodynamic.com/barcodes/USPS-Facing-Identification-Marks-Barcode.aspx
[6]: https://barcodeguide.seagullscientific.com/Content/Symbologies/FIM.htm
[7]: https://github.com/metafloor/bwip-js
[8]: https://github.com/bwipp/postscriptbarcode/wiki/USPS-FIM-symbols
[9]: https://rubydoc.info/gems/ruby-zint/Zint/Fim
[10]: https://about.usps.com/publications/pub25/pub25_ch10_001.htm
[postnet]: https://docs.barcoder.ai/source/standards/postnet
[intelligent-mail-barcode]: https://docs.barcoder.ai/source/standards/intelligent-mail-barcode
[planet]: https://docs.barcoder.ai/source/standards/planet
1. [Facing Identification Mark — Wikipedia][1] — Wikipedia, accessed 2026-10-03
2. [Publication 25, 10-1.2 Using FIMs — USPS][2] — USPS, accessed 2026-10-03
3. [Publication 25, 10-1.3 Patterns — USPS][3] — USPS, accessed 2026-10-03
4. [DMM Revision: New Facing Identification Mark E Pattern — Postal Bulletin 22285][4] — USPS, 2010, accessed 2026-10-03
5. [USPS Facing Identification Marks Barcode — Neodynamic][5] — Neodynamic, accessed 2026-10-03
6. [FIM — Seagull Scientific Barcode Guide][6] — Seagull Scientific, accessed 2026-10-03
7. [metafloor/bwip-js — GitHub][7] — GitHub, accessed 2026-10-03
8. [USPS FIM symbols — BWIPP wiki][8] — GitHub, accessed 2026-10-03
9. [Zint::Fim — ruby-zint documentation][9] — RubyDoc, accessed 2026-10-03
10. [Publication 25, 10-1.1 Overview — USPS][10] — USPS, accessed 2026-10-03
## Deployments
_No country reports mention this standard by name._