How To Fix VSB311 - External transfer &1 already used

SAP Error Message - Details

• Message type: E = Error

• Message class: VSB - Self-Billing Procedure Messages

• Message number: 311

• Message text: External transfer &1 already used

What causes this issue?

The external transfer &V1& has already been used in the internal
transfer &V2& of &V3&.
This transfer however can no longer be assigned to this IDoc.

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

System Response

The IDoc is assigned to a new internal transfer number. For reasons of
security, this transfer is deactivated so that the processing step
cannot be executed. You should now check if the transfer was really sent
twice.
The process, if this is an example of a transfer that has NOT been sent
twice (duplicate) is described below.

How to fix this error?

Check whether this is an example of a duplicate.
If not, you can make settings for the "Duplicate check" in Customizing
(transaction OVD5) so that this is only executed for a specific time in
the past. This is intended if the EDI partner resets external transfer
numbers each year.
In the case that there is no duplicate transfer (the external transfer
number was used last year for example, and now leads to a "false"
duplicate result), you have to proceed as follows:
Set the transfer to active with the function "Set transfer active".
Start the verification step again. The error message that a duplicate
exists, no longer appears.
Eliminate other possible verification errors and then start the
processing step.

Error message extract from SAP system. Copyright SAP SE.