Standards/planet
PLANET
Overview
PLANET (Postal Alpha Numeric Encoding Technique) is a legacy, height-modulated barcode developed by the United States Postal Service to identify and track pieces of mail during delivery as part of the Post Office's Confirm service 1, 2. It was the tracking companion to the routing-focused POSTNET barcode, and its bar pattern is the direct inverse of POSTNET — where a POSTNET digit uses two tall and three short bars, the corresponding PLANET digit uses three tall and two short bars 1, 3, 4. PLANET was fully superseded by the Intelligent Mail Barcode by January 28, 2013 5, 4.
History
- The PLANET barcode (Postal Alpha Numeric Encoding Technique) was developed by the United States Postal Service to identify and track pieces of mail during delivery — the Post Office's Confirm services 1.
- The Intelligent Mail Barcode (IMb) replaced USPS PLANET in 2013 4; PLANET was fully superseded by the IMb by January 28, 2013 5.
(Authoritative sources document PLANET's purpose and 2013 deprecation but do not give a reliable, consistent introduction year; that date is omitted rather than fabricated.)
Technical specification
PLANET is a two-state, height-modulated 1D postal symbology, structurally the inverse of POSTNET 1, 2, 3:
| Parameter | Value |
|---|---|
| Symbology family | 1D height-modulated, two-state (tall / short bars) |
| Length | 12 or 14 digits |
| Per-digit encoding | 5 bars, two-of-five code (3 tall + 2 short — inverse of POSTNET) |
| Framing | always starts and ends with a full (long) frame bar |
| Bar widths/spaces | all bars same width, all spaces same width; data carried by bar height |
| Check digit | modulo-10 (detection only) |
| Character set | numeric only |
Digit encoding — like POSTNET, PLANET uses half- and full-height bars with five bars per digit in a two-of-five code, but here the two-of-five are the short bars (i.e., three tall and two short), making each PLANET digit the height-inverse of the corresponding POSTNET digit 1, 3. The symbol always begins and ends with a long framing bar 1, 3.
Data structure (12-digit form) 2:
| Field | Length |
|---|---|
| Service type | 2 digits (e.g. 21 = Origin Confirm, 22 = Destination Confirm) |
| Mail-piece identification | 9 digits |
| Check digit | 1 digit |
Check digit — chosen as the single digit (0–9) that, when added to the sum of the other digits, makes the total a multiple of 10 1, 3. The check provides error detection only, with no correction 4.
Use cases
- USPS Confirm service mail tracking — PLANET was developed to let mailers uniquely identify and track mail through the Postal Service's Confirm program 1, 3.
- Origin and Destination Confirm — two formats: Destination Confirm tracked outgoing mailings, and Origin Confirm tracked incoming (reply) mail 3.
- Inbound and outbound letter-mail tracking — PLANET barcodes complemented the routing-focused POSTNET barcodes on the same mailpiece, adding tracking visibility for both inbound and outbound letter mail 6.
- Tracked attributes — PLANET-based Confirm tracked mailpiece class, shape, subscriber identification, and custom information such as mailing numbers or campaign IDs 1.
Implementations
- C — zint/zint — 771★, active 2026. Encoding library supporting PLANET among 50+ symbologies.
- JavaScript — metafloor/bwip-js — 2,381★, active 2026. Pure-JavaScript barcode writer supporting PLANET and POSTNET among 100+ types.
- JavaScript decoder — Douglas Boynton Quine publishes a browser-based POSTNET / PLANET / IMb decoder 5.
Comparison
vs. POSTNET — PLANET and POSTNET share the same two-state, height-modulated, two-of-five, modulo-10 framework but serve opposite purposes and are geometric inverses of each other: POSTNET encodes routing (ZIP) data with two tall + three short bars per digit, while PLANET encodes tracking data with three tall + two short bars per digit 1, 3, 4. The two were commonly printed together on a single mailpiece.
vs. Intelligent Mail Barcode — The IMb is a four-state symbology that merges PLANET's tracking data and POSTNET's routing data into one 65-bar symbol with an 11-bit CRC; PLANET is two-state, 12–14 digits, tracking-only, with a single modulo-10 check digit 4. The IMb absorbed PLANET's Confirm-tracking role and superseded it on January 28, 2013 4, 5.
When to choose it — for new mail, never: PLANET is a legacy barcode that should not be used; the Intelligent Mail Barcode is its replacement 4. PLANET remains relevant only for reading or reproducing legacy Confirm-service mailpieces.
Fun facts
- PLANET is one of the few barcode symbologies defined as the exact height-inverse of another symbology — flipping every POSTNET digit's tall and short bars produces the corresponding PLANET digit, a deliberate design so the routing and tracking codes were visually and structurally distinct on the same envelope 1, 4.
- Its acronym, Postal Alpha Numeric Encoding Technique, parallels POSTNET's Postal Numeric Encoding Technique — yet despite the "Alpha Numeric" name, PLANET encodes numeric data only 1.
Status
Deprecated / superseded. PLANET was a legacy tracking barcode that should no longer be used; the Intelligent Mail Barcode is its replacement 4. The IMb replaced PLANET in 2013, with full supersession by January 28, 2013 4, 5. Its successor is the Intelligent Mail Barcode 4, 5.
Sources
- Postal Alpha Numeric Encoding Technique — Wikipedia — Wikipedia, accessed 2026-06-03
- PLANET Barcode — Neodynamic — Neodynamic, accessed 2026-06-03
- USPS Barcode FAQ & Tutorial — BarcodeFAQ.com — BarcodeFAQ.com, accessed 2026-06-03
- Difference Between Intelligent Mail barcode, Postnet and Planet — Dynamsoft — Dynamsoft, accessed 2026-06-03
- USPS POSTNET, PLANET, and IMB Barcode Decoder in JavaScript — Douglas Boynton Quine — quine.org, accessed 2026-06-03
- USPS Intelligent Mail Barcode — Scandit — Scandit, accessed 2026-06-03
Deployments
No country reports mention this standard by name.