GST on Foreign Exchange: Rates, Calculation & Best Practices

GST on foreign exchange applies to the service of converting one currency into another, not to the money itself. When a bank or an authorised dealer facilitates an exchange, the conversion they perform is a taxable service under GST. The currency being swapped is treated as a transaction in money and is never taxed.

The 18% GST is applied to this service value, calculated under Rule 32 of the CGST Rules, 2017, and not to the amount of currency being converted.

If you are an exporter, though, the real question is usually broader: where does GST touch the money you receive from abroad? When an international payment reaches you, GST can appear at three distinct points, and it helps to see them together before going into each one:

The rest of this guide takes each of these in turn, along with how to calculate the conversion GST, how to file, and how to stay compliant.

GST on foreign exchange applies to anyone who converts one currency into another through a bank or authorised dealer. It follows the scope of supply: any time a conversion service is provided, GST applies to that service. That covers a wide set of everyday transactions:

• Buying and selling foreign currency through a bank or authorised dealer
• Sending remittances overseas, such as gifts or education fees
• Loading a forex travel card for an international trip

In each of these, you are paying for a conversion service, so 18% GST applies to the value of that service.

There is one important group this does not catch in the same way: exporters receiving payment from foreign clients. Money coming in for the export of goods or services is treated very differently, and we cover that separately under inward remittances below.

GST on foreign exchange is calculated by applying 18% to the taxable service value, not to the amount exchanged. That service value is worked out using one of two methods under Rule 32 of the CGST Rules: the calculation-based method or the slab-based method. A bank or authorised dealer chooses one method and sticks with it across the financial year.

The two methods are built keeping a couple of things in mind: accuracy and practicality. The calculation-based method values the service by the actual spread earned, which is precise but needs the RBI reference rate for that currency and a per-deal calculation. Since the RBI publishes reference rates only for selected major currencies, and tracking the spread on every transaction is impractical for a busy forex desk, the slab-based method offers a simpler alternative: a fixed formula based on the amount alone, usable even when no reference rate exists, with the service value capped at ₹60,000.

This method looks at the spread, the difference between the rate the bank offers you and the RBI reference rate for that currency.

Example: You sell $10,000 to a bank at ₹85 per dollar, while the RBI reference rate that day is ₹84.5 per dollar. The markup is ₹0.50 per dollar.

Service value = (85 − 84.5) × 10,000 = ₹5,000 GST at 18% = ₹900

When the RBI reference rate is not available: The RBI publishes rates only for selected major currencies. If your currency is not on that list, the service value is taken as 1% of the gross rupee amount received or paid.

When neither currency is INR: Sometimes you convert between two foreign currencies with no rupee directly involved, say USD to GBP to pay an overseas supplier. Here, the service value is 1% of the lower of the two amounts, once both are converted to INR.

GST at 18% would then apply to ₹16,500.

The alternative is a tiered structure based on the total INR amount exchanged:

Example: For ₹15,00,000 exchanged, the service value is ₹5,500 + 0.1% of ₹5,00,000 (the amount above ₹10 lakh), which comes to ₹6,000. GST at 18% = ₹1,080.

GST on foreign currency conversion is 18%, charged on the value of the conversion service, not on the amount you convert. What that service value comes to depends on how your provider prices the exchange. Under the calculation-based method, the taxable value is the spread between the rate you are given and the RBI reference rate. So a provider that builds a wide, hidden markup into the exchange rate creates a larger service value, and 18% GST then applies to that larger base. A provider that charges a clear, flat fee keeps the taxable value, and the GST on it, low and predictable.

One more thing to know: this GST applies to retail customers. Inter-bank forex transactions, meaning conversions between banks or authorised dealers themselves, are exempt.

There is no GST on inward remittances received for exports. If you are an Indian exporter receiving payment from a foreign client, whether you sell services or ship goods, you do not charge GST on those invoices, because these payments are zero-rated exports under Section 16 of the IGST Act.

Zero-rated does not mean exempt. It means you charge 0% GST on your export invoice, but you can still claim Input Tax Credit on the GST you paid on business expenses like software, equipment, raw materials, or rent.

How you qualify depends on what you export. For goods, the supply qualifies as an export when the goods physically leave India for a destination abroad, with the shipping bill as your key piece of evidence. For services, all five of these conditions must be met:

To back up this classification, you need proof of foreign inward remittance, such as a FIRC (Foreign Inward Remittance Certificate) or a bank advice. These show the payment arrived in foreign currency and validate your export status during an audit.

If you are a registered business, it is best to file a Letter of Undertaking (LUT) so you can export without paying IGST upfront. If you do not file an LUT, you must pay IGST on the invoice first and then claim it back as a refund, which blocks your cash for months.

GST does apply to FIRC and BRC, but only to the bank's issuing fee, not to your remittance. When foreign payments land in your account, your bank issues two documents:

• FIRC (Foreign Inward Remittance Certificate): proof that foreign money came into your account
• BRC (Bank Realization Certificate): proof that your export proceeds were realised in India

Banks charge a fee to issue these, usually in the range of ₹500 to ₹2,000 per certificate, and 18% GST is added on top of that fee, because issuing the certificate is treated as a domestic service.

In most cases, this GST is either built into the bank's invoice or handled through the reverse charge mechanism, so it is already taken care of by the time you pay the fee. You do not need to collect any GST from your foreign client for it.

Mistakes here fall into two buckets: getting the tax treatment wrong, and getting tripped up on the GST portal. Both are easy to avoid once you know them.

To file GST for international income, treat it as a zero-rated export: hold an active GSTIN, raise GST-compliant export invoices, export either under an LUT or with IGST paid, and report the income in GSTR-1 (Table 6A) and GSTR-3B. As an Indian business selling to clients abroad, your international income is an export of goods or services, taxed at 0% but still reportable. Here is the sequence:

1. Ensure you have an active GSTIN. You must be registered under GST to report export income and claim its benefits.

2. Raise GST-compliant invoices. Each export invoice should mention "Export of services with payment of IGST" or "Export of services without payment of IGST," carry your GSTIN and the recipient's billing address outside India, and show the currency and conversion rate per the RBI reference.

3. Choose your export route.

• Without payment of IGST: file an LUT annually, charge no GST on the invoice, and claim Input Tax Credit.
• With payment of IGST: pay IGST on the invoice, then claim a refund of the tax paid.

4. File your GST returns. Report export income in GSTR-1 (Table 6A) and GSTR-3B. If you are claiming a refund, file RFD-01 with the supporting documents.

5. Maintain documentation. Keep invoices, FIRA or eBRC, your LUT, and shipping bills (for goods) as required.

The best practices for managing GST on foreign transactions are to use RBI-authorised channels, mark your export invoices clearly as zero-rated, keep the right documents on file, and stay updated on rule changes. A few habits keep your cross-border payments clean and audit-ready:

Use RBI-authorised channels: Always receive and convert foreign currency through RBI-authorised banks or platforms. They apply the correct GST slabs and issue proper, input-credit-friendly invoices.

Mark export invoices clearly: Add a note like "Export of Services, IGST Zero-Rated under Section 16." If your payment partner charges a service fee with GST, make sure that GST shows as a separate line item so nothing gets mixed up.

Keep the right documents on file: The set you want ready includes:

• Form A2 (used for outward remittances)
• FIRC and BRC, as evidence of your foreign currency export proceeds
• Shipping bills and export documents such as invoices and contracts
• Bank statements showing the foreign currency conversion
• Digital copies of all GST documents, including returns and challans

Stay updated: The core GST rules on export of services have been stable since 2017, but minor updates do surface, especially around forex services and compliance documents. Follow a reliable CA or a GST update source so nothing catches you off guard.

Skydo helps with GST compliance by charging GST only on its flat service fee (not on your remittance), issuing FIRA free and instantly with every payment, and giving you GST-compliant invoicing, live forex rates, and transparent flat fees. Instead of chasing your bank for certificates and second-guessing what GST applies, you get everything in one place.

Transparent, flat fees. Skydo's pricing is simple and predictable:

GST only on the fee, never on your payment. Skydo charges 18% GST on its flat service fee, not on your remittance. Receive $10,000 and the fee is $29, so the GST is 18% of $29, roughly $5.22. Because the fee is flat and the rate carries no hidden spread, the taxable value stays small and you know your GST in advance, instead of it ballooning inside a marked-up exchange rate.

FIRA, instant and free. Every payment comes with a FIRA the moment it lands, so you have your compliance proof ready without a bank fee or the GST on it.

GST-compliant invoicing. Raise clean, zero-rated export invoices that carry the right details out of the box, so your paperwork holds up at filing and audit time.

Live forex rates. You see the real rate you are getting, with no hidden markup buried in the spread.