For: Anyone managing payment requests via Prommt.
If every payment on your account is failing — not just one — see Troubleshooting: all payments failing on your account instead. This article covers individual payment failures only.
Step 1 — Find the Payment Gateway Response
Every failed payment in Prommt carries a Payment Gateway Response — the reason for the failure as reported by your payment gateway. This is the first and most important thing to check.
Go to View Payments in your Prommt dashboard
Find the failed payment and click to open it
Look for the Payment Gateway Response field
The response text tells you exactly what went wrong. The sections below explain the most common responses and what to do for each.
Common failure reasons
"Do Not Honor" / "Declined"
What it means: The customer's bank has refused the transaction. This is the most generic decline code — the issuing bank is blocking the payment but hasn't given a specific reason.
What to do:
Ask the customer to contact their bank directly. Banks often block unusual or high-value transactions as a precaution, even for legitimate payments — a quick call usually resolves it.
The customer can also try a different card if they have one available.
This is not something Prommt or your payment gateway can override.
"Insufficient Funds"
What it means: The card doesn't have enough available balance or credit to cover the payment amount.
What to do:
Let the customer know the payment couldn't be processed due to insufficient funds.
Ask them to use a different card or arrange an alternative payment method.
"Expired Card"
What it means: The card has passed its expiry date and can no longer process transactions.
What to do:
Ask the customer to use their updated card. Most banks issue replacement cards automatically — the customer may have a new card with a different expiry date they haven't activated yet.
"Authentication Failed" / "3D Secure Failed" / "SCA Required"
What it means: The payment requires the customer to complete a security verification step — typically a code sent to their phone by their bank, or an approval in their banking app. The authentication was not completed successfully.
This is the most common cause of individual payment failures in the UK and Europe. Under Strong Customer Authentication (SCA) rules, all online card transactions require this step. Prommt applies 3D Secure 2 on every card payment — it's the customer's bank that sends and verifies the authentication.
What to do:
Resend the payment request and ask the customer to complete the authentication step when prompted. They'll need to have their phone to hand and be ready to act quickly — authentication codes expire within a short window.
If the customer repeatedly can't complete authentication, the most common causes are:
Outdated phone number with their bank — the authentication code is going to an old number they no longer use. They need to update their details with their bank.
Corporate or company card — if the cardholder is not the person completing the payment (e.g. a PA paying on behalf of an executive), the authentication challenge goes to the registered cardholder, not the person at the checkout. The cardholder needs to be available to approve.
Banking app not set up — some banks require the customer to have their mobile banking app installed and connected. If it isn't, they may not receive the authentication prompt.
Prommt cannot bypass 3D Secure authentication. If the customer's bank requires it and the customer can't complete it, the card cannot be used for online transactions.
"Invalid Card Number" / "Invalid Card"
What it means: The card number entered at checkout doesn't match a valid card. Usually a data entry error.
What to do:
Ask the customer to try again and double-check the card number, expiry date, and CVV as they enter them.
If this persists, the customer should try a different card or contact their bank.
"Transaction Not Permitted" / "Card Not Enabled for This Transaction Type"
What it means: The customer's card is blocked for this type of transaction. This can happen with prepaid cards, certain corporate cards, or cards with online transaction restrictions applied by the cardholder's bank.
What to do:
Ask the customer to use a different card — a standard personal debit or credit card will typically work where a restricted card doesn't.
If the customer believes their card should work, ask them to check with their bank whether online transactions are enabled.
"Duplicate Transaction"
What it means: The gateway has detected what looks like a repeated charge for the same amount within a short window. This is a fraud-prevention measure.
What to do:
Wait a few minutes before resending or retrying the payment.
If the original payment actually went through, check the status in View Payments before sending a new request — you don't want to charge the customer twice.
No response or blank field
What it means: The payment failed before reaching the gateway, or the gateway did not return a response. This is not a standard card decline — it indicates a connectivity or configuration issue.
What to do:
Check that your account is in Live Mode and your gateway is connected. See [Troubleshooting: all payments failing on your account].
If your account settings look correct and this is happening on multiple payments, contact Prommt Support via the chat button in your dashboard and include the payment reference and approximate time of the failure.
ECI code errors
You may see an ECI code in the Payment Gateway Response alongside — or instead of — a text description. ECI (Electronic Commerce Indicator) codes are two-digit codes that indicate the outcome of the 3DS2 authentication step on a card transaction.
The key codes to know:
ECI Code | Scheme | Meaning |
05 | Visa | Full authentication — payment protected |
02 | Mastercard / Amex | Full authentication — payment protected |
06 | Visa | Attempted authentication — partial protection |
01 | Mastercard / Amex | Attempted authentication — partial protection |
07 | Visa | No authentication — contact Prommt Support |
00 | Mastercard / Amex | No authentication — contact Prommt Support |
ECI 07 or ECI 00 on a Prommt payment request is unusual and should be investigated — Prommt applies 3DS2 to all card transactions as standard. If you're seeing these codes, contact Prommt Support with the payment reference.
For a full explanation of ECI codes and what they mean for chargeback liability, see [Understanding ECI codes on failed payments].
If the customer has already paid but the status still shows as failed
Before resending a payment request, always confirm the status in View Payments.
In rare cases there can be a short delay between a successful payment and the status updating. If the status hasn't updated after a few minutes and the customer is certain they completed payment, contact Prommt Support with the payment reference — do not send a duplicate request until this is confirmed.