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When the internet drops — keep selling, sync later

What a shop till should do when the connection goes down, the questions to ask any online POS, and a short checklist so a dropped line never stops the queue.

By the CreekPOS team 5 min read

When the internet drops — keep selling, sync later

Sooner or later the internet in your shop will stop. Usually it is back in a few minutes, but a few minutes at the evening rush or just before iftar is a long queue of customers who will not wait. Whether those minutes cost you sales depends on decisions you make long before the line drops.

Why the connection drops

In a small shop the cause is rarely dramatic:

  • the router restarts, overheats in a hot storeroom, or someone unplugs it to charge a phone;
  • a short power cut takes the router down, even if the PC is on a battery;
  • road or building works damage a cable;
  • the provider has an outage in your area.

Most of these last minutes, a few last hours. Your plan should cover both.

What "works offline" should mean

Many systems say they work offline. Ask exactly what keeps working. These are the questions that matter at the counter:

QuestionA good answer
Can the till keep selling?Yes, with the same products, prices and promotions as a moment ago
Does the customer get a receipt?Yes, printed as usual, with a receipt number
What happens to stock?It is deducted locally and corrected on the server when the till reconnects
What happens on reconnection?Sales are sent in the order they happened, without duplicates
Can a sale be counted twice?No; each sale is sent once and the server refuses a copy
What about cash and shifts?The drawer, cash in and out, and the shift close keep working

If the answer to the first question is "the screen shows an error", you have a system that needs the internet to sell. That may be fine for an office, but not for a counter.

Three kinds of systems

KindSells without internet?Notes
Program on the shop PC, data in files on that PCAlwaysNothing to sync; backups are your job
Online system with a till that can work offlineYes, then syncsData on a server; owner sees all tills and branches
Browser page that needs a live connectionNoStops when the line stops

None of these is wrong in itself; the third is just a poor fit for a busy counter. For help choosing between the first two, see which one is right for you.

Receipt numbers while offline

A receipt number must be unique. When a till cannot reach the server, it cannot ask the server for the next number. A careful system solves this in a visible way: it prints a provisional receipt number that clearly belongs to that till, then the sale gets its place in the record when it arrives at the server. The sales are sent in the order they were made, so the day's sequence stays readable for you and your accountant.

The card terminal is a separate question

Your bank's card terminal has its own connection. Some terminals use the shop's internet, some have a mobile SIM, some can switch between the two. Ask your bank what yours does, and whether it can fall back to mobile data. If the terminal is down as well:

  • put up a small "cash only for now" sign at the counter instead of discovering it at the end of each sale;
  • for regular customers with a monthly account, recording the sale on their account is often the easiest way through;
  • record any card sales correctly once the terminal is back, so the shift totals still match. See cash and card shifts.

A checklist for the day the line drops

  1. Put the router on a small UPS, together with the till PC. A five-second power dip should not cost you the connection.
  2. Keep a backup connection: a mobile hotspot or a 4G/5G router with a data plan, set up and tested in advance.
  3. Connect the receipt printer by USB or on the local network. A local printer does not need the internet.
  4. Know who to call: the provider's number and your account number taped inside a cupboard door.
  5. Run a drill once: unplug the router for five minutes during a quiet hour and sell. Find the surprises before a busy evening does.
  6. Keep the router cool: not in a closed cupboard next to the fridge compressor, especially in summer.

What waits until the line returns

A till can sell offline; the rest of the world cannot see those sales until the till reconnects. The owner's phone dashboard, stock levels seen from another branch and e-mailed summaries catch up when the connection returns. That is normal. What should never happen is a lost sale or one counted twice.

In CreekPOS

CreekPOS comes in two editions. The Windows program bought once per register keeps all data in files on the shop PC and never needs the internet to sell; backups go to a USB drive or folder on a schedule. CreekPOS Online keeps your data on servers in the EU, encrypted and backed up daily, and its tills keep selling when the internet drops: each till works from a local copy, prints a provisional receipt number, and sends its sales in order when the line returns, with nothing doubled. Details are on the online page.

Quick answers

How long can a till sell offline? A well-built offline till keeps selling until the line returns; the longer the gap, the longer the owner's reports wait for the catch-up.

Will prices I change at home reach the till while it is offline? No; changes reach the till when it reconnects. Avoid price changes during a known outage.

Do I still need backups with an online system? The provider backs up the server; keep your own exports for your records too.

Is a phone hotspot enough as backup? For a single till, often yes. Test it at your busiest hour first.

Want to try it on your own counter? Open the live demo or start a 14-day trial with your own products.

This article is general information as of its date, not legal or tax advice. Rules change; check the official source or ask your accountant before acting.

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CreekPOS Online free for 14 days, or the program on your PC for 7 days. Every feature, no card.

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