In shops, restaurants, and pharmacies today, almost no transaction avoids the internet. The till app syncs stock to the cloud, the card terminal contacts the bank, QR payments wait for a notification, and delivery-app orders arrive on a tablet.

When that connection stutters, the queue stops. So the network for payments needs treating differently from the Wi-Fi handed out to customers.

Keep it apart from customer Wi-Fi

This is the first rule and the one most often broken. Two reasons:

  • Speed at busy times. When the shop is full, dozens of customer phones compete with the till. That is exactly when most transactions happen.
  • Security. Unknown devices on the same network as the till computer are an unnecessary risk. Transaction data and the till app's account must not be reachable from a customer's phone.

Almost every router can create a separate guest network. The till, card terminals, order tablets, receipt printer, and admin computer sit on the staff network; customers on the guest network with client isolation on. How to do it is in the guide to separating guest networks.

Cable for what doesn't move

The till computer and network receipt printer almost never move. Cable them. Wi-Fi at the counter is often disturbed by metal shelving, fridges, and microwaves, and a brief interruption is enough to fail a transaction.

Tablets and card terminals carried to customers' tables stay on Wi-Fi. Make sure the signal is strong across the whole service area, not just near the till.

A plan for when the internet goes down

The shop's internet will go down one day, a provider fault, a cut cable, or a power cut. What matters is what happens next:

  • A backup connection. A router with a backup mobile modem, or a hotspot from a dedicated shop phone, keeps the till running. The options are in the guide to backup internet for businesses.
  • A SIM in the card terminal. If supported, an active SIM is a second path that doesn't depend on the shop router.
  • A small UPS for the router and ONT, so a flicker of power doesn't cut the connection for several minutes.
  • The till app's offline mode. Check whether your app can record sales without internet and sync later. Train staff on it before it is needed.

QR payments left "hanging"

The tensest moment at a till is a customer who has paid by QR while the till screen shows nothing. The cause is often on the shop's side: the notification didn't arrive because the connection stalled.

Set a simple procedure: never ask a customer to pay again before checking the transaction history in the merchant app. A customer charged twice remembers it far longer than a slightly longer queue.

Basic security

  • The staff network password is not given to customers or posted near the till.
  • The router admin password is not the default.
  • Till app accounts are not shared; each staff member has their own if the app supports it.
  • The staff network password is changed when an employee leaves.

Keep the payment network apart from customer Wi-Fi, cable devices that don't move, and prepare backups before you need them: a second connection, a SIM in the terminal, a UPS, and offline mode. For a QR payment that doesn't show up, check the history before asking the customer to pay again.

Frequently asked questions

Can tills use the same Wi-Fi as customers?

Better not. Apart from speed when the shop is busy, customer devices on the same network could potentially reach till equipment. Payment systems belong on a separate staff network.

Should a card terminal use a SIM or Wi-Fi?

Many terminals can use both. Reliable Wi-Fi or cable is usually faster inside the shop, while a SIM is useful as a backup when the shop's internet is down. Setting up both is the calmest option.

What happens if the internet drops during a QR payment?

The payment can succeed on the customer's side while the till never receives the notification. Don't treat the payment as failed before checking the transaction history in the app or the account statement, so the customer isn't charged twice.