Oracle R12 – APPS-SQL-10000: ORA-01400: Cannot insert NULL into


I am facing a strange error that seem to have inter-connections between PO/AP and ETax, and I thought I ask if you might have come across this before??

 The scenario is as follows:
          Standard PO is created in OU = France for a Supplier based in the UK (EXPECTED TAX = OFFSET VAT) 
            Enter Invoice in AP by Matching invoice to PO an Invoice Line is created
          The following Error message is displayed when pressing the Calculate Tax button
Cannot insert Null into Oracle R12 Tax 
If a PO is entered for a Supplier based in the same country than the OU (France in this case), then the PO Match works perfectly, including Tax calculation, and there is no error message.
Similarly, if an invoice is entered against the UK based Supplier without matching to a PO, then the Tax calculation works perfectly, without error message.
Any hint or idea would be greatly appreciated

Solution provided:

 I have come across this issue before. First I would be advising that you turn tax off on the POs, there is no need to have it if you recover 100% VAT and it does cause issues like the one you are seeing.

One of the causes could be that in PO, it cannot calculate offset taxes, only the positive VAT part. So the tax on the PO will be wrong anyway, it will be say FR VAT EU AP GOODS 20% and won’t have the FR OFF EU AP GOODS 20%. If you are forcing the tax rate in from the PO, then it could be causing the issue as AP would want the Offset tax.

Change the settings below to remove the ‘enforce’ options and this should fix your issue.