Calculating Tax

 11.5.10.02

Hi all

I am having a problem with GCT on prepayment. This the senario. I created a gct tax code name "GCT" at rate 16.5 % , at the bigging of this financial year the gct rate increase to 17.5%. What i did was to enddate the GCT tax code "GCT" at 16.5 % as at 31-Dec--09and create a new Tax code with the same name "GCT" at 17.5% effective 01-Jan-10.

In Dec-09 we entered some prepayment with tax code GCT at 16.5% , now we are paying those prepayment final invoice. When I entered the final invoice to apply with date 16-Jan-10 ans apply the prepayment the system calculates tax on the prepayment at 17.5% instead of the 16.5% that was originally calculated on it when it was paid. Therefore we are understating the supplier final payment.