Hsn code for works contract

DEAR SIR,

I WOULD LIKE TO KNOW WHAT IS HSN CODE FOR WORKS CONTRACT. I AM WORKING IN A SUB CONTRACTOR FIRM. WE SUBMIT BILL TO OUR MAIN CONTRACTOR. NOW MY DOUBT IS, WHEN WE PREPARE A BILL TO SUBMIT, I HOPE THAT MENTION HSN CODE FOR A PARTICULAR SERVICE. PLEASE INFORM ME WHAT OS HSN CODE FOR WORKS CONTRACTS.

THANKING YOU

DGKUMAR