Guides & TutorialsPayments & Currency Payment Gateways2Checkout MD5 Hash Failures - June 2020

2Checkout MD5 Hash Failures - June 2020


We've been made aware of a technical issue at 2Checkout which results in some transaction failing to be recorded in WHMCS.

An entry in the Billing > Gateway Log within the WHMCS Admin will display the result MD5 Hash Failure

We have identified a release made on the June 4th which is calculating the hash sent inside the INS incorrectly. This can cause INS to be rejected when the notification is validated.


A fix for the issue has been deployed by 2Checkout as of 08:00 UTC on 5th June 2020.

No update is required to the WHMCS software.

2Checkout will resend the affected INS notifications, and these will be recorded by WHMCS.

Further Information

For further information on this matter, please contact 2Checkout support: