Square UK: Troubleshoot Payments

tranguyen — Sun, 21 Sep 2025 13:12:50 GMT

Hi Seller Community ✨!

As a business, it can be frustrating and a bit awkward when customer cards are declined no matter how common this situation is. Customers may assume the worst but sometimes the reason their card is declined may have nothing to do with their finances.

In this post, we’ll run through some common error messages you’ll see when a payment is declined, why payments may be declined and what you can do in these situations.

Before we dive in, please make sure you’ve checked the following:

✔️ You’ve linked a bank account to Square. Square sellers are required to have a bank account linked to Square before taking payments. You won’t be able to accept payments until your bank account has been linked and verified.

✔️ Your Square Point of Sale app is up to date. For security reasons, and to ensure PCI compliance, Square will no longer process chip card or contactless payments on devices running versions of the Square app that are older than 90 days. Learn more about updating your Square app in our Support Centre.

✔️ Your hardware is set up and ready to use. It’s worth running through some troubleshooting steps to rule out any issue with your hardware:

How can you tell if a card has been declined?

📝 Note: Square is not given the exact reason why a card is declined but the error messages below can give you some insight on next steps for handling declined payments.

If a card is declined in the Square Point of Sale app, you’ll see one of the following errors:

“Declined. Card has expired. Please use a different card.”

“Declined. Please use a different card.”

“Declined. Please have cardholder call issuer before retrying transaction.”

“Declined. Please verify the card number, expiry date, CVV and postcode.”

“Failure Charging Customer”

What can I tell the customer?

Telling a customer their card was declined can be an uncomfortable conversation. The best approach is to be as understanding as possible. Most people have experienced a card payment declined at least once in their life, but it can still be awkward.

You can explain to the customer that their bank has declined their card. If they are paying in person, they may see the declined message themselves.

Here are some steps for handling declined payments:

[1] Confirm the card is valid

You’ll want to make sure that card is valid. Sometimes customers forget to replace an expired card with the new one sent to them.

[2] Check the customer’s information

For manually entered transactions, Square requires 100% accuracy. The information entered must match the payment card exactly. Verify with the customer that you have all the correct details for them.

✨ Tip: A card’s number will turn red if the information is entered incorrectly to the Point of Sale app, so it could be a data entry mistake. In these cases, we always recommend asking the customer to repeat the long number on the card and that should help the transaction go through.

If your customer has confirmed their card is valid and the transaction still declines, they should contact their card-issuing bank for more information.

Should I retry a declined payment?

Sometimes a customer will ask you to try the card again. Before doing so, it’s best asking the customer to contact their card issuer (typically via a toll-free number found on the back of their card) to look into a potential problem. You can attempt the transaction again once the problem has been cleared or the payment has been pre-approved.

🔍 Tip: Contacting the card issuer can help rule out the potential for fraud. A common reason for cards to be declined is due to potential misuse. If the purchase looks suspicious, it’s not uncommon for them to decline the transaction.

I didn’t get a declined message but I can’t see recent transactions in my report. What’s going on?

If you didn’t get a declined message but transactions are not showing up in your Transactions tab, it’s likely that the transaction was voided. That means the payment wasn’t successfully captured and the cardholder was not charged.

There are two ways a payment can become voided:

Payments can be manually voided from the pin screen by tapping the “x” in the top-left corner before it completes processing.
Payments are automatically voided if they aren’t finished within 5 minutes or if the Point of Sale app is interrupted. Square requires an active internet connection at all times to process card payments. Always check that you have a strong network connection before attempting to process a payment. A good way to test the speed of your network is to open a new mobile browser and confirm the speed in which the page loads. Payments can fail if the connection is not strong enough.

📡 Tip: If you don’t have mobile data on your phone and would like to get a backup for internet wherever you are, you may want to consider getting a WiFi dongle. You can buy one from your local provider or online.

How can I tell a payment is successful?

Here are some steps you can take to check if a payment has been successful:

✔️ A payment is not completed until you’ve passed the “Thanks. You’re all Done” screen.

✔️ If your payment was successful and you’ve opted in to receive notifications, Square will send you an email (i.e. “Square Payment 123456”)

✔️Check if the transaction appears within the Transaction tab in your app or on your Dashboard. If the transaction is not completed, it will not appear here.

✔️ For split payments, it’s important to make sure that the full balance has been processed for the entire sale to be successful (e.g. if you’ve split a bill in half and completed the first half of the sale by card and issued a receipt for the payment, if the remaining balance isn’t collected, the first transaction will be voided). Be sure to tap ”New Sale” after a split bill to confirm you’ve processed the split bill in full.

I can’t see the transaction in my account but the customer can see it on their bank statements. What does this mean?

If the transaction does not show up in your account but appears on a customer’s card statement, this is a sign that your customer is seeing a pending transaction and not an actual charge.

If a payment is cancelled, interrupted, voiced or declined, it can result in pending charges on your customer’s bank statement. Square immediately sends the void notification, but it may take the bank a few business days to remove the pending charge or release reserved funds.

💳 Tip: Pending charges typically display within parenthesis e.g. (£10) or within the Pending Transactions section within your customer’s online statements.

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