Service tax

Hi

ours is proprietory concern doing electric contract work & registered under service tax under works contract.

during current quarter we have raised bill under two different heads. i.e. one only for labour charges for electric wiring in building where we have charged service tax of 12.3.6% and other bill of works contract for electrical work with material where we have charges vat @ 5% & service tax @ 4.326 after abatement (70%).

my question is service tax collected @ 4.326 % has to be paid under works contract head.

but under which code should i pay service tax collected @ 12.36% .

Thanks in Advance