vat accounting

for output two ledger codes are necessary and not for input

I think NO, Total Input VAT(whether it may be 4% or 12.5%) can be set off with available Output vat (both 4% and 12.5%) 

THE CORRECT ACCOUNTING IS OPEN SEPARATE LEDGER INPUT 4% AND 12.5% AND OUTPUT 4% AND 12.5% AND THEN AT THE END OF QUARTER/ MONTH WHEN SALES TAX DUE DR OUTPUT ENTRIES AND CREDIT INPUT ENTRIES AND BALANCE IS UR TAX PAYABLE