The line will drop
Fibre gets cut, a router restarts, a provider has a bad evening. None of it is unusual, and none of it waits for a quiet hour. The question is not whether a branch will lose its connection, but what the people at the counter can still do when it happens.
What a till needs on hand
To keep trading without the internet, a till has to hold locally everything a sale depends on: the items and their prices, the open tickets and tables, the cashier's permissions and the receipt layout. Then it can keep taking orders, taking payments and printing receipts and kitchen tickets as if nothing had happened.
A system that asks a distant server for each price, or saves each ticket only there, stops the moment the line does. Staff fall back to paper, and someone types it all in later.
What happens when the line comes back
While it is offline, the till keeps a queue of everything it did. When the connection returns, the queue is sent to the central database in the order it happened. Nobody re-keys anything, the reports catch up, and no sale is lost or counted twice.
This is how BranchPOS works: the terminal holds the catalogue and the open tickets locally, keeps taking payments and printing, and replays its queue when the line returns.
What it does not cover
Offline-first keeps the till working; it does not make the rest of the world work offline. Card payments still need the bank's network: if the card terminal cannot reach its bank, take cash. Orders from delivery apps reach you only while the place that receives them is online. A good system tells you plainly which parts need a connection.
How to test it
Pull the network cable in the middle of a sale. Keep selling for a few minutes, print a receipt and a kitchen ticket, then plug the cable back in and check the sales report. If you want to see it with BranchPOS, book a demo.