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 PLANET was fully superseded by the intelligent-mail-barcode by January 28, 2013 [5, 4].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• The intelligent-mail-barcode (IMb) replaced USPS PLANET in 2013 [4]; PLANET was fully superseded by the IMb by January 28, 2013 [5].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

1. Postal Alpha Numeric Encoding Technique — Wikipedia — Wikipedia, accessed 2026-06-03
2. PLANET Barcode — Neodynamic — Neodynamic, accessed 2026-06-03
3. USPS Barcode FAQ & Tutorial — BarcodeFAQ.com — BarcodeFAQ.com, accessed 2026-06-03
4. Difference Between Intelligent Mail barcode, Postnet and Planet — Dynamsoft — Dynamsoft, accessed 2026-06-03
5. USPS POSTNET, PLANET, and IMB Barcode Decoder in JavaScript — Douglas Boynton Quine — quine.org, accessed 2026-06-03
6. USPS Intelligent Mail Barcode — Scandit — Scandit, accessed 2026-06-03

Deployments

No country reports mention this standard by name.