Stamp Decoder

Modern GB

In-app purchases

About this app

Scan · Decode · Collect.

Modern GB Stamp Decoder helps you explore modern Great Britain barcoded stamps and keep a digital record of the items you own. Built for collectors of QEII and King Charles III stamps, it brings scanning, the Modern GB digital Catalogue and your own collection together.

SCAN AND DECODE
Scan a supported stamp's Data Matrix barcode with your camera, or paste the barcode text. No stamp to hand? Open the example decode to see how it works. Read the decoded information alongside matching catalogue details, including face value, colour, issue date, barcode generation date and security overlays where available.

YOUR DIGITAL COLLECTION
Save your own stamps, booklets and sheets in clearly separated sections. Record the condition and visible characteristics of your copies, with booklet details kept distinct from the stamps inside. Saved observations belong to your collection; they are not replaced by catalogue updates.

CATALOGUE AND CHECKLIST
Browse the Modern GB digital Catalogue using our own MGB references. Use the separate checklist to see what you have and need, organised by stamps, booklets and other collecting formats. Choose a simple checklist or separate Mint and Used boxes, and search or filter the catalogue to focus on your interests.

GUIDED COLLECTOR CHECKS
Compare security backing paper using a step-by-step visual guide. Open it from Scan or while recording an item. Use SBP or PB names in Settings, and choose “I'm not sure” when a characteristic cannot be established.

OPTIONAL PRO FEATURES
Start with free stamp decoding and save up to 25 collection items. Five free Collector Checks let you try the guided identification tools. An optional Pro subscription adds unlimited collection saves and Collector Checks, enhanced catalogue detail, advanced decoding features, and Stamp card image and print tools. See the in-app purchase screen for prices and subscription terms.

ON YOUR DEVICE
No collection account is required. Decoding and collection storage work on your device. Use Back up to keep a separate copy of your saved collection. Cloud collection synchronisation is not included in this version.

Decoding and catalogue matching provide collecting information, not proof that a stamp is genuine or valid for postage. Some details require you to examine the physical stamp, booklet or sheet.

Some images used with permission of Royal Mail © 2026. Not a Royal Mail product.
© 2026 Modern GB Stamps.

Privacy policy: https://stampdecoder.app/privacy/

What’s new

Scan · Decode · Collect with clearer navigation and a refreshed digital collection. Open the catalogue directly, identify backing paper with guided comparisons, and see saved stamps and booklets in consistent colour-coded panels. Includes clearer booklet steps, an updated Stamp card, reference-data updates and collection recovery improvements. Collections remain on your device; cloud sync is not included.