Where single payment does not exceed Rs. 20,000 or aggregate payment does not exceed Rs. 50,000:

No deduction from payment made to a contractor or sub contractor is to be made if the amount credited or paid in pursuance of any contract the consideration of which does not exceed Rs. 20,000. Further, where the aggregate of the amounts of such sums credited or likely to be credited or paid during the financial year exceeds Rs. 50,000, the person responsible for paying such sums shall be liable to deduct income tax.

Thus the tax will be required to be deducted at source where the amount credited or paid or likely to be credited to a contractor exceeds Rs. 20,000 at One time or Rs. 50,000 in aggregate during a financial year in spite of the fact that separate contracts are entered into with that person.