i am facing the prob in account determination.
I am giving u the info help me out.
only output tax is allowed for account 175000 companycode, ZA not allowed(error)
Goto FS00 and enter your G/L account number and goto control data over there. You have tax category field which is marked as "+" because of which only output tax is allowed. You can make that as "*" which allows all kind of taxes. This would release the billing document. Check with your FI consultant if it is with this particular G/L if you make that change.