Error Code 12: Invalid Transaction (2024)

As a business owner, coming across error code 12 is familiar territory when accepting credit cards. Imagine your customer gives you their credit card, you swipe it, and decline code 12 appears on the machine. Now the customer feels frustrated and the line of people behind them grows impatient as you scramble to figure out why the terminal says invalid transaction. There are a variety of reasons why a credit card transaction does not go through. Understanding what error codes are and what they mean, can help you troubleshoot the situation and soothe your customer. Read on to learn what decline reason code 12 means and how to resolve it on your credit card reader.

Invalid Transaction: What It Means

In the case of an error code 12 credit card decline, this means the issuing bank will not accept the transaction. The decline reason code 12 comes straight from the issuing bank or the bank associated with the customer’s credit card. This means for some reason, the issuer is declining the payment transaction attempt invalid, resulting in an error code. There are many reasons you may get an invalid transaction message. Some possible causes for the error include:

• Incorrect card number.The most common reason for a decline reason code 12 is simply due to keying in the credit card number wrong.
• The card itself is invalid.The card may have been flagged or canceled for suspicious activity.
• Expiration date issues.It is possible that the cashier accidentally mistyped the expiration date when keying in the card information. Another common cause is that the card has expired.
• Strange activity.Depending on the POS System, if the merchant tries a unique request like refunding a refund, the system may not know how to handle it and show error code 12.
• Multiple transactions in a row.If you try to run a card various times in quick succession, safety measures will kick in. These are in place to prevent fraud or multiple charges and will decline the transaction after a few attempts.
• Address verification service error.If the customer accidentally keyed in the wrong zip code, the system will see that it’s different from their address. If the information doesn’t match, the terminal will return error code 12.

What is an Error Code?

An error code is a signal from your payment processor that alerts you when a credit card transaction did not go through. There are dozens ofcredit card error, hold, and decline codes, each with its definition to help you understand the underlying cause of the decline. Usually, your payment processor or merchant service provider will give you a guide to all the decline codes. In any case, it’s important to know and understand what each one means. Error codes help you determine why a payment couldn’t go through, which allows you to troubleshoot the issue for your customer. Some error codes are more specific than others and are relatively easy to resolve. Others can be a little vague and may require outside help. So, what does an error code 12 mean then?

How to Resolve Error Code 12

Now that you understand what error code 12 means, you can simply go through the list of possible causes and try to resolve them. You can also print a list of error codes and their causes and keep it handy for when you receive another code alert.

However, if none of these issues apply and all the card information is accurate, then there is a larger issue. In this case, have the customer contact their issuing bank to solve the problem. In the meantime, you’ll have to ask them for an alternative method of payment.