A 0.4% payment fee sounds like ₹40 on a ₹10,000 purchase. But if the product attracts 18% GST, the payment is ₹11,800. Charge 0.4% on that full payment, then add 18% GST to the processing fee, and the merchant's gross deduction becomes ₹55.70.
The arithmetic is right under those assumptions. The important questions are what the fee is charged on, who pays it, and whether the merchant can recover the GST through input tax credit.
The ₹10,000 example, step by step
This is an illustration of a taxable payment-processing service: product price ₹10,000 before GST, product GST 18%, MDR 0.4% of the full amount processed, and GST on MDR 18%. It assumes no exemption, fee cap, minimum fee or other charge. These are example rates, not a claim that every purchase or payment method attracts them.
- Product price before GST: ₹10,000.00
- GST on the product: ₹10,000 × 18% = ₹1,800.00
- Customer's payment: ₹10,000 + ₹1,800 = ₹11,800.00
- MDR on the full payment: ₹11,800 × 0.4% = ₹47.20
- GST on that MDR: ₹47.20 × 18% = ₹8.496, approximately ₹8.50
- Total processing deduction: ₹47.20 + ₹8.496 = ₹55.696, approximately ₹55.70
If both amounts are deducted during settlement, the merchant receives approximately ₹11,744.30, before any other adjustments. This is a settlement figure, not profit or a calculation of the merchant's final GST liability.
Why 0.4% becomes about 0.56%
The percentage changes depending on the amount used as the denominator:
- Against the ₹10,000 pre-GST product price: ₹55.696 ÷ ₹10,000 × 100 = 0.55696%, or approximately 0.56%.
- Against the ₹11,800 actually paid: ₹55.696 ÷ ₹11,800 × 100 = 0.472%.
The underlying MDR rate remains 0.4%. The higher figures describe the combined fee and GST cost before input tax credit.
0.4% × 1.18 × 1.18 = 0.55696% of the pre-GST price.
The first 1.18 includes the product's GST in the processed payment. The second adds GST to the fee. Different product tax rates, fee arrangements or exemptions change the result.
Where the “fee on a tax” concern comes from
The MDR can be split into ₹40 on the product price and ₹7.20 on the ₹1,800 product GST. The latter is the part that prompts a fair question: why should the merchant pay a percentage processing fee on money collected as tax?
In a hypothetical alternative where the same 0.4% fee applied only to ₹10,000, the fee would be ₹40 and GST on it ₹7.20, totalling ₹47.20. Charging on ₹11,800 instead increases the combined amount by ₹8.496, approximately ₹8.50 before input tax credit. That comparison illustrates the effect of the fee base; it is not a statement that merchants are currently entitled to exclude product GST.
A fee calculated on a tax-inclusive payment, followed by tax on that fee: the cost deserves a clearer explanation than a headline percentage.
Calling this “tax on tax” captures the frustration, but it compresses two different things. MDR is a payment-service fee, not itself a government tax. The later GST is charged on that service fee. This arithmetic alone does not establish unlawful double taxation.
Who pays: the merchant or the customer?
Axis Bank describes MDR as a rate charged to the merchant for debit- and credit-card services. Its merchant guidance also says the transaction amount includes charges and taxes levied to the customer. That helps explain why a percentage fee can use the gross payment as its base. The exact rate and charging terms must still be checked in the merchant agreement. Axis Bank payment-acceptance FAQs.
In this example, the customer pays ₹11,800. The ₹55.70 is not automatically an additional bill for the customer. If a checkout adds a separate charge, that is another fact to examine; MDR does not by itself authorise a surcharge. Axis Bank's cited merchant guidance expressly tells its merchants not to surcharge.
Businesses may consider payment costs when setting prices, so customers can be affected indirectly. How much gets passed on is a commercial question; this example does not prove that every merchant passes on the entire amount.
GST on the fee—and the input-credit caveat
Payment providers distinguish the transaction value from their service fee. For example, Razorpay explains that 18% GST applies to its processing fee rather than to the whole payment. Its provider pricing is an example of this structure, not evidence that its rate is 0.4% or that every payment service has identical tax treatment. Razorpay's fee and GST explanation.
Eligible GST-registered merchants may claim input tax credit for GST on a qualifying business service. Section 16 of the CGST Act sets conditions for credit; registration alone is not enough. Eligibility, the invoice, business use, supplier reporting and applicable restrictions need to be checked for the merchant's situation. CBIC: Section 16, eligibility and conditions for input tax credit.
If the full ₹8.496 credit is eligible and usable, the processing cost after that credit is ₹47.20: 0.472% of the pre-GST product price, or 0.4% of the payment. The settlement deduction and timing of credit utilisation remain separate matters.
If credit is unavailable, the approximately ₹55.70 remains the gross processing cost in this illustration. Do not assume either that every merchant can recover the GST or that none can. A merchant should reconcile the provider's tax invoice with their GST records and check eligibility with their accountant.
This is a calculation, not a universal payment charge
Do not read the 0.4% example as a new charge on every card, UPI transfer or QR payment. Payment instrument, provider, merchant category, contract, effective date and any applicable exemptions matter. An MDR, a gateway/platform fee and a customer convenience fee are different charges and should not be silently treated as interchangeable.
If no MDR is charged, there is no GST amount arising from that nonexistent MDR. Separately charged taxable services may still need their own treatment. When a policy announcement circulates, check its issuing authority, commencement date and covered transactions rather than applying a screenshot to every payment.
Five questions for your payment provider
- What amount is the fee calculated on? Ask whether it uses the full GST-inclusive payment and request a worked settlement example.
- What does the quoted rate include? Separate MDR, platform fees, GST, minimum charges, caps and recurring charges.
- Which payments does it apply to? Get the payment methods, merchant categories, exceptions and effective date in writing.
- What tax invoice will I receive? Ensure the business details are correct and identify where the invoice and settlement report can be downloaded.
- What is my actual cost? Compare gross deductions and eligible, usable tax credit separately. Confirm the treatment of refunds as well.
My view: a merchant should be able to see the quoted rate, the fee base, the GST and the final deduction together. Policymakers and providers should also explain the case for charging on the tax portion of a payment. Small percentages are easier to judge when their rupee consequences are visible.
Calculation and source notes
Checked on 29 September 2026. All calculations use the stated assumptions and retain full precision before rounding displayed rupee totals to two decimal places. Actual invoices may apply their own permitted line-item rounding.
This is a worked explainer with editorial commentary, not an announcement of a new universal MDR or a personalised tax determination. Product GST, payment-service GST and credit eligibility must be checked independently. The central point is precise: in the stated example, a 0.4% fee produces a gross processing cost of about 0.557% of the pre-GST product price.