The register does not wait for your signal
Once a card is on the device, its barcode is available with no internet connection. Store Wi-Fi and a dead spot in the basement do not block checkout.
You can still edit
Offline is not a read-only mode. You can add a card, change a balance, or log a transaction without a connection. Those edits are queued on the device. The next time the phone has a connection, CardWarden syncs them on its own. You do not have to remember to push the changes.
What has to be on the device already
A brand-new phone with an empty local copy cannot invent cards that were never synced to it. Sign in and let the wallet download once while you have a connection. After that, checkout and edits work offline, and the queue catches up later. Sync itself is part of Premium Cloud and Premium Family.
