Free
$0/forever
What you're using right now
- 100+ barcode & QR symbologies
- Live preview & customization
- PNG & SVG export, no login
- Copy to clipboard
Loading Barcode Mint…
Free Online Barcode & QR Code Generator
Create a scannable Royal Mail Mailmark 2D barcode for UK letters and large letters that need item-level tracking.
Open the generator ↓Turn a CSV — or a numbered sequence — into hundreds of barcodes at once, exported as a ZIP of images or a print-ready PDF sheet. Launching with Pro.
The browser generator stays free forever. Paid plans are for teams who need bulk output and developers who need the REST API at scale — commercial license included. Tell us what you'd use; early-list members get first access and launch pricing.
What you're using right now
For designers & teams
Priced by requests. Commercial license and self-serve keys included; usage dashboard at launch.
Royal Mail Mailmark 2D is a Data Matrix barcode that Royal Mail uses to sort, route and track letters and large letters across the UK postal network. It replaced the older 4-state Mailmark barcode on many mail streams because a 2D Data Matrix can hold far more information in the same footprint and stays readable even with minor print defects. Mailmark 2D is the format required for mailings that need full item-level track-and-trace, such as Mailmark Tracked and Mailmark Tracked 24/48 services.
Unlike a plain Data Matrix generated for general use, a Mailmark 2D symbol carries a strictly defined data structure that Royal Mail's sorting machinery expects. Getting that structure wrong means the mail item either gets rejected at induction or routed incorrectly, so mailers work from Royal Mail's published Mailmark specification rather than free-text input.
A Mailmark 2D payload is built from fixed and variable fields defined by Royal Mail and the Universal Postal Union (UPU), including:
Because these fields are position- and length-defined, Mailmark 2D data is typically generated by print/mailing software that already holds the customer's Royal Mail licence details, rather than typed by hand.
Royal Mail Mailmark 2D is carried in a Data Matrix symbol (ISO/IEC 16022, ECC 200 Reed–Solomon error correction), encoding a fixed-format record defined jointly by Royal Mail and the Universal Postal Union's S25 Format Control Code standard. The payload mixes numeric and alphanumeric fields — UPU FCC, Mailmark barcode ID, version ID, class, supply chain ID, item ID, and postcode/delivery point data — each with a strictly defined position and length rather than free-text input. Royal Mail specifies minimum X-dimension (module size) and quiet-zone requirements to ensure reliable reads at the sortation speeds used by its automated equipment; there is no separate human-readable check digit exposed to mailers, since data integrity relies on the Data Matrix's own error correction plus Royal Mail's back-end validation of the supply chain ID and item ID against the mailer's registered licence.
Mailmark 2D appears almost exclusively in UK business mail production, including:
You won't typically see Mailmark 2D on international mail leaving the UK, or on mail handled outside Royal Mail's network — it is specific to UK domestic sortation and Royal Mail's own tracking infrastructure.
Barcode Mint renders the Mailmark 2D symbol as a Data Matrix once you supply a correctly formatted payload string. To create one:
/barcode?type=mailmark2d&data=... to generate symbols on demand from your mail merge system.Always validate a sample run against Royal Mail's Mailmark test tools or your mailing software's built-in validator before a live mailing — an incorrectly structured Mailmark 2D symbol can cause an entire batch to be rejected at the mail centre.
Mailmark 2D is read by high-speed optical sorting equipment, so print quality matters more than it would for a barcode scanned by hand. Keep contrast high (black symbol on white or light background), maintain the specified quiet zone around the Data Matrix, and avoid printing over folds, perforations or envelope windows where distortion or occlusion could prevent a clean read. Test print samples at your actual production print resolution and stock before running a full mailing, since low-resolution or low-DPI printers can blur the fine modules of a dense Data Matrix symbol.
Compared with Royal Mail 4-State (RM4SCC) and Mailmark 4-State, which encode a limited set of height-modulated bars carrying mainly postcode and a short reference, Mailmark 2D's Data Matrix format holds substantially more structured data — full item-level IDs, supply chain identifiers, and class information — in support of Mailmark's item-level tracking services. Compared with a generic Data Matrix generated for general use, a Mailmark 2D symbol looks identical as a barcode but is meaningless to Royal Mail's sortation systems unless its payload follows the exact UPU/Royal Mail field structure and comes from a mailer with a valid Mailmark licence and supply chain ID.
A royal mail mailmark 2d generator produces the Data Matrix barcode Royal Mail uses to sort, route and track UK letters and large letters, encoding fields like mail class, supply chain ID and item serial number.
You can render the Data Matrix symbol itself with any correctly formatted data string, but to use it on live mail with Mailmark postage and tracking you need a Royal Mail Mailmark licence and an approved supply chain ID.
Yes — use the bulk CSV to ZIP/PDF tool to generate a unique Mailmark 2D symbol per row, which is how large transactional and direct mail runs assign a distinct item ID to every piece.