# Preventing Stamp Fraud: What a Digital Stamp Card Has to Be Able to Do > Self-stamping, shared QR codes, or repeat abuse: we walk through the mechanisms a digital stamp card needs — staff scan, traceable stamp issuance, daily limits, and QR protection. Canonical: https://reloop.cards/en/blog/stempelbetrug-digitale-stempelkarte-verhindern Published: 2026-04-30 Updated: 2026-08-02 Author: reloop Team (candybytes GmbH) --- export const metadata = { title: 'Preventing Stamp Fraud: What a Digital Stamp Card Has to Be Able to Do', description: 'Self-stamping, shared QR codes, or repeat abuse: we walk through the mechanisms a digital stamp card needs — staff scan, traceable stamp issuance, daily limits, and QR protection.', publishedAt: '2026-04-30', updatedAt: '2026-08-02', category: 'Security', tags: [ 'Stamp Fraud', 'Anti-Fraud', 'Staff Scan', 'Security', 'Digital Stamp Card', ], readingMinutes: 9, }; A digital stamp card should be easier than paper — but not less secure. If guests can give themselves stamps or pass QR codes around freely, the program quickly loses its value. That's why a professional solution needs clear control at the register. In this article, we run through the most important mechanisms a digital stamp card should bring to the table to keep your program fair — for you, your team, and your regulars. ## The problem: self-stamping The most common mistake in basic loyalty apps is a "stamp now" button that's visible to guests. The moment someone can tap that button without your team being involved, the model falls apart: stamps get handed out at home, on the bus, or during a lunch break — that is, without you actually having seen the person. A digital stamp card should therefore rest on one clear principle: stamps are issued by authorized staff, not via a freely accessible guest button. ## Solution 1: staff scan instead of self-service With a staff scan, your team issues the stamp through a logged-in account or a specially set-up register device. The guest shows the pass in their wallet, your team scans back — the stamp is added. Advantages: - There's no visible "self-stamp" button. - Stamps are only issued when the guest is actually on site. - The flow fits your normal register process: pay, scan, done. Important: your team should have its own login or its own QR code so that stamp issuances can be tied to a role and a point in time. ## Solution 2: traceable stamp issuance (audit log) A professional solution records, at minimum, when each stamp was issued and by which staff member. reloop keeps an audit log for this: every stamp is logged with a timestamp, staff ID, and card ID. That delivers three things: - **Transparency within the team.** You can trace how stamp issuances are distributed across shifts. - **Error diagnosis.** If a guest says "my stamp is missing," you can look it up instead of guessing. - **Trust for business customers.** For branches, franchises, or multi-location setups, traceability isn't a nice-to-have — it's a requirement. Even if your setup doesn't need to use the audit log actively, traceable stamp issuance still helps in the background — as the technical foundation that ensures stamps don't land on the card "somehow." ## Solution 3: daily limits Some guests want to stamp multiple times on the same day, often by accident or "because it's on their mind." A stamp card should therefore let you configure a daily limit per program — typically one stamp per day per card. Daily limits help: - They prevent unintentional double stamps. - They counter attempts to stamp multiple times during a shift change. - They make the reward fair: no one "wins" through speed, only through genuine repeat visits. What matters is that the daily limit fits your program. For a lunch stamp card, one stamp per day makes sense; for a card with a morning and afternoon reward, the limit can be higher. ## Solution 4: QR protection and short validity windows If a QR code used for stamp issuance can simply be photographed and passed around, you have the same problem as self-stamping — just a bit more indirect. A professional solution should therefore: - use QR codes with short validity windows (e.g. a few seconds to minutes), - sign or rotate QR codes so that screenshots don't keep working indefinitely, - draw a clear separation between the guest QR (on the wallet card) and the staff QR (in the team's login area). The goal isn't to block every theoretical manipulation — it's to make repeat abuse harder with minimal effort. For café or salon programs, that's enough in practice. ## What a stamp card shouldn't promise Claims like "guaranteed fraud-proof" or "100% tamper-proof" aren't honest in a wallet world. The point is to create friction so that abuse costs more than an honest stamp — not to rule out every technical possibility. A professional stamp card should therefore communicate clearly: we rely on controlled stamp issuance, traceable campaigns, and technical safeguards. That keeps the program fair without you needing a giant security apparatus. ## Sample calculation: when is the effort worth it? Imagine you issue 20 wallet stamps a day. Without safeguards, it only takes a handful of guests stamping multiple times to see the reward statistically handed out far more often than it's actually earned. If every reward carries a material cost for you, that adds up fast. With a staff scan, an audit log, and a daily limit per card, this "gray area" largely disappears. That's not a guaranteed saving — but it's a realistic lever for any wallet stamp card that gets handed out in the real world. ## Conclusion A digital stamp card doesn't need a security fortress, but it does need clear mechanisms: a staff scan instead of self-service, traceable stamp issuance, daily limits, and QR protection. Together they keep your program fair — and make sure the guests who genuinely come back get their reward. More background on security and data protection: [Security & data protection for reloop](/datenschutz-und-sicherheit) Test a digital stamp card with controlled stamp issuance and a staff scan. Try a secure stamp card