1. GOV.UK One Login QR
GOV.UK One Login is the UK government's centralised identity platform. QR codes are used in the identity verification flow: the user scans a QR displayed on their desktop browser from their mobile, which opens the mobile verification flow for ID document scanning and selfie capture — a cross-device handoff pattern.
2. DVLA Digital Driver's Licence
The DVLA is piloting a digital driver's licence accessible via the DVLA app. A QR generated by the app allows police, employers, and rental car companies to verify the licence holder's current entitlement without calling the DVLA. The QR encodes a signed, time-limited token.
3. W3C Verifiable Credentials and QR
The W3C Verifiable Credentials (VC) standard defines a format for cryptographically signed digital credentials. A QR can encode a VC or a link to a VC presentation. The verifier scans the QR, cryptographically verifies the issuer's signature, and confirms the credential is valid and untampered.
Common uses in development: digital age verification, professional qualifications, and health certificates (e.g., vaccination records).
4. Zero-Knowledge Proofs for Privacy
Advanced VC implementations use zero-knowledge proofs: instead of disclosing the full credential (e.g., full date of birth for age verification), the credential proves a derived claim ("I am over 18") without revealing the underlying data. The QR carries the proof, not the data.
5. Security Considerations
Digital identity QR tokens must be:
- Short-lived (expire within minutes for in-person verification, hours for online).
- Signed by the issuing authority (prevent forgery).
- Bound to the device or biometric to prevent transfer.
- Revokable (the issuer can invalidate a token before expiry if the credential is withdrawn).
Putting this into practice
Start with the smallest real test you can run. Generate the code, print it at the exact size you plan to use, and scan it with two different phones in the lighting where it will live. Check that the destination page loads quickly on a mobile connection and that the call to action next to the code tells people what they will get. If anything feels slow or unclear, fix it before you print a full batch, because reprints cost more than a short test. Keep a note of the size, material, and placement that worked so the next batch starts from a proven setup.
Common mistakes to avoid
The most common mistakes are easy to avoid once you know them. Long payloads make modules tiny, low contrast makes edges hard to read, and text placed too close to the border eats the quiet zone the scanner needs. Covering a corner finder pattern with a logo or a sticker breaks detection entirely, and a code placed behind glare or on a curved surface fails even when the print is perfect. Review each of these points on a proof copy, and treat any failure as a reason to adjust the design rather than a reason to blame the scanner.
Quick checklist
- Keep the payload as short as practical so modules stay large.
- Keep dark modules on a light background with strong contrast.
- Leave a clear quiet zone on all four sides of the symbol.
- Test the printed code at the real viewing distance and lighting.
- Confirm the destination page loads fast on a phone.
- Recheck the code after any change to the link, design, or placement.
Related tools and guides
- Use the [QR size calculator](/qr-size-calculator) to match the printed size to the expected scan distance before you commit to a print run.
- The [error correction simulator](/error-correction-simulator) shows how damage tolerance changes the density of the symbol at each level.
- The [pet tag QR](/pet-tag-qr) page covers codes that help a finder reach the owner.
- Test every code with the [QR scanner](/qr-scanner) on more than one phone before you publish or print it.
- Create a fresh code with the [URL QR code generator](/url-qr-code-generator) when the destination is a web page.
- Run unfamiliar destinations through the [QR safety checker](/qr-safety-checker) before you share a code widely.
