There are two ways a stamp can get added to a customer's card on Primo, depending on which one a shop has switched on.
Staff-added stamps
The most common way: after a customer pays, a staff member finds them in the dashboard and taps "add stamp." It updates instantly on both sides — no page reload, no waiting.
Rush-Hour QR Stamping
On Pro and Premium plans, shops can also switch on self-serve stamping — a QR code customers scan themselves to add their own stamp, which is useful when a queue is moving fast and staff don't have time to tap "add stamp" for every single order.
To keep this safe, the QR code isn't static — it refreshes automatically every few seconds. A screenshot or photo of it stops working almost immediately, and the system also blocks the same scan from being counted twice in a row, so there's no way to repeatedly scan the same code for extra stamps.
What if the connection drops for a second?
If a stamp can't be saved right away because of a brief connection hiccup, it isn't lost. It's automatically retried, and if it still can't go through immediately, it's queued and added within a minute once the connection is back — nobody needs to notice or do anything differently.