Royal Mail Mailmark generator

Royal Mail Mailmark — the Royal Mail 2D code on UK letters.

A string in the Royal Mail format: “JGB ”, 41 characters of service data, then your data (up to 90 in total).

Check a code

PDF and print use the chosen width. Print at 100% scale, not “fit to page”.

How to print a code that scans
  • Print at 100% scale — the 100 mm ruler on the print sheet shows if the printer resized it.
  • The white margins are already in the file: don’t crop them or put text or a frame right next to the code.
  • Dark code on a light background. Test red ink, glossy film and clear labels with a proof first.
  • Don’t shrink a barcode too much: EAN-13 and UPC-A at standard size are about 37 mm (1.47 in) wide.
  • Before a print run, print one sheet and test it with the scanner people will actually use.
  • “Ready” on this site means an independent software reader decoded the code. It is not an ISO or GS1 certificate.

You can check this code on the home page: by camera, from an image or a screenshot.

Your code

Enter data on the left and your code appears here.

Create codes from a spreadsheet

Royal Mail Mailmark from a spreadsheet

Paste a column from Excel or Google Sheets or choose a CSV file. Each row holds the code data and, if needed, a label in the second column. We check every row against the Royal Mail Mailmark rules.

Fill with sequential numbers

Paste a table — the first codes and a row-by-row report will appear here.

Unlock batches with your key

After payment, Lemon Squeezy emails you a key. Paste it here to unlock batches on this device.

How to unlock batches
  1. Choose a plan and pay on the Lemon Squeezy page.
  2. Your key arrives in the purchase email.
  3. Paste the key here and press “Activate”.

See pricing

Lost your key? It’s in the purchase email and in your Lemon Squeezy orders: app.lemonsqueezy.com/my-orders

New computer: first press “Remove key” on the old one. Old one unavailable? Write to us and we’ll free the slot manually — the address is in Terms & refunds.