2 Tax Code, 2 Condition Types

Dear Gurus,

I have the following condition types.

1. PR00

2. MWST  >> Access sequence Z001 >> tax code Y1 >> tax GL 10011001

3. ZSED   >> Access sequence Z002 >> tax code Y2 >> tax GL 10011002

both step 2 and 3 have the same reference 1, means MWST will calculate on PR00 value and ZSED will also calculate on PR00 value.

when I post the invoice with out ZSED system successfully save it and if at invoice level both taxes are coming system give error message in MWST posting. "FF753 message number.

if for resolution of above error I change the category of ZSED from tax to discount/surcharge system can easily post it but in that case system shows ZSED value in net value not in tax field.

Please suggest the solution.

Looking for the response.

regards,