A shop app that keeps selling when the internet does not
Every shop app says it works offline. Most mean the screen still opens. Duka365 means the sale completes: the customer pays, the receipt goes out, the stock comes down, and the record waits on the phone until there is signal to send it. Nothing is lost, nothing is counted twice, and nobody at the counter has to know any of it happened.
What actually happens when the network drops
The till stops taking payments, so the shop falls back to a notebook and somebody types it all in later.
It does not stop. A sale rung up with no connection is written to the phone straight away, complete with what was sold, at what price and what was paid. It is a finished sale from the shop’s point of view — the only thing outstanding is telling our servers about it. The takings on your screen include it immediately.
When the connection comes back, the same sale gets sent twice and the day’s figures are wrong.
Every sale is named by the phone before it is sent, with an identifier the server checks. If a reply is lost and the phone retries — which is exactly what happens on a weak connection — the server recognises the sale it already has and returns it rather than writing a second one. Duplicates are not cleaned up afterwards; they are never created.
The app refuses a sale because its stock count is out of date, and the goods are visibly on the shelf.
A stock check is a door, and a door can only be shut in front of somebody. If the sale already happened, refusing it does not un-sell the goods — it only deletes our record and leaves the shop’s takings short. So the sale is kept, and you get an alert asking you to count that product, which is the real problem.
The phone’s clock is wrong after a week without a network, and the sales come back dated wrong.
Cheap handsets drift, and one that has been offline has had nothing to correct itself against. A sale that arrives dated in the future is kept and dated on arrival rather than thrown away. Losing a real sale to a wrong clock is not a trade worth making.
You have to sign in to use it, and signing in needs internet.
It does not. The session is held on the device and trusted for two weeks without contact, so a shop with no signal for days opens the app and sells. Signing out does not discard queued sales either — they are the shop’s records, not the phone’s.
A day with no network, start to finish
- 1
You open the shop and the app. It opens on the till, with your whole catalogue on the phone — prices, stock, customers — because it was copied down the last time there was signal.
- 2
A customer buys three things. You tap them in, take the cash, and the sale is recorded. An amber strip at the top says the phone is working offline and everything will be sent once it is back.
- 3
Someone buys on credit. You add them as a customer there and then, and the debt is recorded against them. Both were named on the phone, so they still line up when they arrive.
- 4
A crate of soap is delivered. You add the count from the shelf. Nothing about that needs a network.
- 5
Signal comes back at four. The queue empties in the background while you carry on selling — no button, no waiting screen, and no risk of sending anything twice.
- 6
At home that evening you open the dashboard on a laptop and the day is there, whole.
Questions people ask before they trust it
- How long can the shop run with no internet at all?
- Two weeks on one device without contacting our servers. In practice most shops reconnect long before that — a few minutes of signal is enough to empty the queue.
- What happens if the phone breaks while sales are still queued?
- Those sales are on that phone and nowhere else, so they would be lost — the same as a notebook that gets wet. It is the honest answer, and it is the reason the app sends as soon as it can rather than batching, and tells you on the Today screen exactly how many are still waiting.
- Can two people sell on two phones at the same time with no network?
- Yes. Each phone records what it sold and both queues arrive independently. Stock counts settle once both have sent, and if the two disagree with the shelf you get an alert to count it rather than a silent guess.
- Does it work on a cheap Android phone?
- Yes. It is a small download, it holds the catalogue locally rather than fetching it, and it does not need a fast connection because most of the time it does not need one at all.
- Is the offline part only on the paid plans?
- No. The app, and everything above, is on every plan including the free one. The paid plans lift the ceilings and add reporting, staff accounts and branches.
Try it where the signal is worst
Start free, put it on the counter phone, and turn the data off. If it does not sell with the network down, nothing else on this page matters.