GST TDS Section 51 Calculator for Government Contracts
When you supply goods or services to a notified government body under a contract above Rs 2.5 lakh, the payer withholds 2 percent of the taxable value as GST TDS. This calculator shows the deduction and what hits your bank.
Your numbers
TDS applies when the value of the supply under a contract exceeds Rs 2,50,000. Value excludes GST.
Your results
Applies to notified deductors such as government departments, local authorities and certain agencies. Confirm the deductor status and the contract value test for your case.
GST TDS versus contract value
Sweeps Taxable value of the contract invoice (excluding GST) from 100000 to 2000000, holding your other inputs fixed.
Track government TDS receivables in your ERP
Optional: ask how to reconcile GST TDS certificates to receipts inside your ERP.
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How to use the calculator
Enter the taxable value of the invoice, the GST rate and the place of supply. The tool tests the Rs 2,50,000 threshold, computes the TDS and splits it into CGST, SGST and IGST. It also shows the net receipt after any retention or penalty. The chart sweeps contract value so you can see the jump when the threshold is crossed, which helps when planning invoice sizes.
How Section 51 works
Section 51 of the CGST Act requires notified deductors to deduct tax at 2 percent, split as 1 percent CGST and 1 percent SGST for intra-state supply or 2 percent IGST for inter-state supply, on the payment to a supplier of taxable goods or services where the contract value exceeds Rs 2,50,000. The deductor files GSTR-7 and issues a TDS certificate through the portal. The amount appears in your electronic cash ledger once the deductor files.
- Threshold is tested on the contract value
- Deduction is on taxable value excluding GST
- The deductor files GSTR-7 by the 10th of next month
- You accept the credit in GSTR-2A or GSTR-2B and cash ledger
Worked example
A contractor invoices a state department Rs 12,00,000 plus 18 percent GST, which is Rs 2,16,000. TDS is 2 percent of Rs 12,00,000, which is Rs 24,000, split Rs 12,000 CGST and Rs 12,000 SGST. Net payment is Rs 13,92,000. The Rs 24,000 reappears in the contractor's cash ledger and is used against the monthly tax liability.
Common mistakes
Suppliers often fail to check the credit on the portal, leaving TDS unused for months, or compare TDS to the GST-inclusive invoice. Accounts teams also forget to book TDS receivable and then see an apparent short payment. Reconcile each deduction against the GSTR-7 certificates every month.
- Not matching TDS to GSTR-7 data
- Using GST-inclusive value for the 2 percent
- Not accepting or using the cash ledger credit
- Treating TDS as a customer short payment
Frequently Asked Questions
Who must deduct GST TDS?
Notified persons, mainly government departments and establishments, local authorities, governmental agencies, and certain PSUs and societies. Private companies are not deductors under Section 51 unless notified. Check the deductor's status before assuming TDS will apply.
Is the Rs 2.5 lakh threshold per invoice or per contract?
It is based on the total value of the supply under a contract. If a contract is above Rs 2,50,000 in total, deduction applies even to invoices that are individually smaller, according to common departmental practice, so verify with the deductor.
How do I use the TDS credit?
The deducted amount is credited to your electronic cash ledger when the deductor files GSTR-7 and you accept it. You then use it to pay output tax in the same way as any cash deposit.
Is GST TDS the same as income tax TDS?
No. GST TDS is a separate deduction under the CGST Act and is reported in GSTR-7. Income tax TDS under Section 194C or others may also apply to the same payment, so both can reduce the net receipt.
If government receivables are showing unexplained short payments, we can help set up TDS receivable tracking and reconciliation in your ERP.
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