Used by 700,000+ people
Free Royal Mail 4-State barcode generator.
RM4SCC, Royal Mail's former Customer Barcode (CBC), carries a UK postcode and delivery point suffix. Enter both as one string; the generator adds the check character.
How to create a Royal Mail 4-State barcode
-
01
Join postcode and DPS
Use capitals, drop the space and append the DPS: SN3 4RD with DPS 1A becomes
SN34RD1A. The generator does not check the postcode format. -
02
Choose 300 dpi
Leave Module width at Fit (default) and choose Resolution (dpi) 300. A fixed module width shortens the bars.
-
03
Leave 2 mm clear
Download PNG and leave 2 mm free on all sides. The Quiet zone setting enlarges the bars rather than adding 2 mm.
What is the Royal Mail 4-State Customer Code?
The Royal Mail 4-State Customer Code (RM4SCC) puts a UK postcode, a two-character delivery point suffix (DPS) and a check character into four kinds of bar, for automated letter sorting. Mailmark replaced this CBC option after 2017.
Barcoded letters until 2017, then Mailmark
In 2014, Royal Mail accepted the barcode on machine-readable letters, not large letters. In a Barcode posting, at least 90% of items (95% for some services) needed an accurate DPS.
The option ended after 31 December 2017; Royal Mail recommended Mailmark or OCR. Its April 2026 Account Barcode Unsorted guide still gives Mailmark Barcode D the CBC's bar dimensions.
Check character, contrast and bar sizes
The check character exposes misreads; start and stop bars let machines read the code either way round. Print contrast ratio: at least 40%; bars must not be lighter than the background.
At Fit and 300 dpi, the generator's bars measure 0.51 mm at 24 per inch, track 1.35 mm. At 96 dpi the track reaches 1.59 mm, over Royal Mail's 1.52 mm.
Online, in a data sheet or with TBarCode
Single barcodes are free as GIF, PNG or JPG, no account needed; a plan adds SVG and higher print resolution. Address lists need a data sheet and a free sign-in.
TEC-IT software encodes RM4SCC as symbology 70 and adds the check character: TBarCode SDK in Windows applications, TFORMer Server with ERP data, TBarCode API over HTTP.
Royal Mail 4-State at a glance
- Data
- Postcode (5–7) and DPS (2): 0–9, A–Z
- Bars
- 0.38–0.63 mm wide, 20–24 per inch
- Track
- 1.02–1.52 mm; ascender, descender 1.60–2.16 mm
- Clear zone
- At least 2 mm, all sides
- Specification
- Royal Mail user guide, chapter 17 (2014)
From postcode to check character
| Part | Pattern (A letter, N digit) | Example |
|---|---|---|
| Outward code | AN, ANN, ANA, AAN, AANN, AANA, AAA | SN3 |
| Inward code | NAA | 4RD |
| DPS | NA | 1A |
Royal Mail's table sets 0–9 and A–Z in six rows and columns, numbered 1–5 and 0. Sum the data characters' row numbers modulo 6, then their column numbers. SN34RD1A: rows 22, remainder 4; columns 27, remainder 3; row 4, column 3 is K.
Frequently asked questions
Learn more about Royal Mail 4-State.
Does Royal Mail still accept RM4SCC?
Is the Mailmark 4-state barcode the same?
What is a DPS?
Is Singapore Post's 4-state code the same?
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