BAPI_ACC_DOCUMENT_POST and Official number for Italy BKPF-XBLNR_ALT

Question

Hello,
Italy lesgislation imposes every accounting document must have an Official number (VAT number).
This number has to be located in BKPF-XBLNR_ALT and can be set automatically with a standard customizing (using range number). The relevant function is OFF_NUMBER_GLOBAL_NUMBERING_IT
Using FB01, there is no problem, the standard uses the customizing to set this number in relevant field.
But using ACC_DOCUMENT.ACC_DOCUMENT02 Idoc and thus BAPI_ACC_DOCUMENT_POST because some documents comes from an external system, this is not done.
Do you have an idea ?
Could you help us ?
I already find this post on the subject but answer not provided :
XBLNR_ALT
Thanks a lot.
J.C.

Answer 1

hi,
see oss note 806173 (and another)
[Note 806173 - Empty reference (XBLNR_ALT) when documents posted with IDoc|https://service.sap.com/sap/support/notes/806173]
Extrait
Summary
Symptom
You are using official document numbering for Italy (see note 746162). You post an accounting document with IDoc FIDCCP02, comming from an external system. In the target system no official document number is generated and thus field XBLNR_ALT remains empty.
Other terms
XBLNR_ALT, alternative reference number, FIDCCP02
Reason and Prerequisites
Reason
This case is not yet considered.
Prerequisites
Italian company code
Note 746162
Solution
The accounting interface is enhanced in order to create an official document number in the target system, if an accounting document is created using IDoc FIDCCP02 coming from an external system.
The official document number is only generated if field XBLNR_ALT is initial. If the official document number is already created in the external source system, no new official document number is generated. The value of field XBLNR_ALT is taken over to the source system instead. In this case you need to set up carefuly the number ranges for the official document numbers in the source and target systems. You need to ensure that the same official document number is not assigned more than once to different documents.You can ensure this for example, by using different number ranges for each document type.
Header Data