Postal Business plan

Royal Mail 4-State Barcode API

UK postal service customer barcode

Sample Royal Mail 4-State barcode

SN34RD1A

Generated live by the BarGen API from SN34RD1A

Royal Mail 4-State Customer Code, commonly abbreviated RM4SCC, is the height-modulated barcode Royal Mail developed for automated mail sorting in the United Kingdom. Like the USPS Intelligent Mail Barcode, it encodes data across four bar states, ascender, descender, tracker, and full bar, but its payload is built from the UK postcode and delivery point suffix rather than a numeric tracking code, letting sorting machines route mail directly by address.

Call the BarGen REST API with a UK postcode and delivery point suffix to generate an RM4SCC symbol, returned as SVG or PNG sized to Royal Mail's printing specification for envelopes and mailing labels.

Royal Mail 4-State Customer Code (RM4SCC) is a barcode used by Royal Mail, the UK postal service, for automated mail sorting. It encodes the postcode and Delivery Point Suffix (DPS) to route mail to the correct address.

The barcode uses four bar states similar to other postal codes: full bar, ascender, descender, and tracker. It can encode uppercase letters A-Z and digits 0-9, allowing the full UK postcode format plus delivery point information.

RM4SCC is designed for Cleanmail and Mailsort services, which offer discounts for pre-sorted mail. Mailers who print the barcode on their mail pieces receive reduced postage rates in exchange for reducing Royal Mail's sorting workload.

The barcode includes start and stop characters plus a check digit for error detection. When properly printed in the delivery address area, it enables automated sorting at high speeds, reducing manual handling and improving delivery times.

Common use cases

UK automated mail sorting

Royal Mail sorting equipment reads RM4SCC to route letters directly to the correct delivery office and postal round.

Direct mail campaigns

UK direct mail printers encode RM4SCC on mailing pieces to qualify for Royal Mail's machine-sortable discount rates.

Returned and redirected mail processing

Mail handling systems use RM4SCC to identify and reroute undeliverable or forwarded items automatically.

Generate Royal Mail 4-State via the REST API

curl "https://api.bargen.pro/v1/barcode/rms4cc?data=SN34RD1A&format=svg" \
  -H "X-API-Key: YOUR_API_KEY"

Returns the barcode as SVG; PNG, PDF and EPS are available on higher plans. See the API documentation for all options.

Frequently asked questions

What data does an RM4SCC barcode encode?

It encodes the UK postcode together with a delivery point suffix, plus a checksum, letting sorting machines identify the exact address without reading the printed text.

Is RM4SCC still used alongside Royal Mail Mailmark?

Royal Mail has been migrating large mailers to the 4-state Mailmark barcode, but RM4SCC remains in use for many existing mailing systems and lower-volume senders.

How is RM4SCC different from USPS Intelligent Mail Barcode?

Both use a four-state bar height encoding, but RM4SCC is built around UK postcodes while IMb is built around US ZIP codes and USPS tracking identifiers, so the two are not interchangeable.

Specifications

Character Set
A-Z, 0-9
Structure
Postcode + DPS + Check digit
Bar States
4 (full, ascender, descender, tracker)

Availability

Available from the Business plan.

See pricing

Start generating Royal Mail 4-State barcodes

Free tier with 1,000 API calls per month. No credit card required.