Transfer posting of tax in a cross company code transaction thru' RFBUST10

Hi,

I have a doubt regarding using the program RFBUST10 transferring the tax in a cross company transaction.

I have posted an invoice entry as below and I want to transfer the tax posting of 7.00 from company code 1 to company code 2 using the program RFBUST10.

Cr - 31 - 3rd party vendor - total amount of invoice co code 1 - 214.00

Dr - 40 - expense account - 100.00 co code 1 - C7 (Tax code at 7%)

Dr - 40 - expense account - 100.00 to co code 2 C7 (Tax code at 7%)

I have successfully posted and the tax amount of 7.00 is also transferred from company code 1 to company code2 but now I have 2 problems:

1) The program (RFBUST10) is permitting to transfer tax for the same cross- company code document multiple times. Please let me know how to track whether the cross company code document is already processed for transfer posting of tax.

2) In the transfer posting document as below ,the tax code in the first line item (clearing account) is defaulted to C0 , I would like to know from where this tax code defaults, I have not maintained the default tax code in the GL master.

Dr - 40 clearing Account 107 - C0 (tax code 0%)

Cr- 50 clearing account 100 - C7(tax code at 7%)

Cr - 50 Tax account 7 C7

Please let me know how to resolve these issues.

Tks

SS