How to File LUT for GST Exports: A Step-by-Step Portal Guide

Under the Goods and Services Tax (GST) framework, all exports are considered "zero-rated" supplies. This means the tax rate on the final export is 0%. However, exporters have two choices:

1. Pay the Integrated GST (IGST) upfront and then claim a refund.
2. Export without paying any tax by filing a Letter of Undertaking (LUT).

For most small exporters, service providers, and startups, filing an LUT is the preferred choice. It prevents your working capital from getting blocked in the government's refund system, allowing you to ship goods or provide services globally with zero tax outlay.

This guide explains the eligibility rules for LUT and the step-by-step process to file Form GST RFD-11 for the 2026-27 Financial Year.

What is a Letter of Undertaking (LUT)?

An LUT is a formal declaration made by an exporter to the GST department. In this document, the exporter "undertakes" (promises) to:

• Export the goods or services within the statutory time limit.
• Pay the tax plus interest if they fail to export the goods within the deadline.
• Comply with all export-related GST laws.

Once filed and accepted, the LUT is valid for the entire financial year. You do not need to file a new LUT for every invoice; one LUT covers all your exports from April 1 to March 31.

Who is Eligible to File an LUT?

Almost all registered taxpayers can file an LUT, provided they meet these simple criteria:

1. They intend to export goods or services (or both).
2. They have not been prosecuted for a tax evasion offense exceeding ₹2.5 Crores under the CGST Act or the IGST Act.

Note for New Registrations: Even if you just applied for your GSTIN today, you are eligible to file an LUT immediately as long as you haven't been prosecuted in the past.

Legal Reference

Relevant Law: Rule 96A of the CGST Rules, 2017 prescribes the conditions for exporting goods or services without payment of integrated tax under a Letter of Undertaking (LUT). Section 16 of the IGST Act defines Zero-Rated Supplies.

Step-by-Step: How to File LUT (Form RFD-11)

The entire process is digital and takes less than 10 minutes on the GST portal.

Step 1: Log in and Navigate

• Log in to the GST Portal.
• Go to Services > User Services > Furnish Letter of Undertaking (LUT).

Step 2: Select Financial Year

• Select the Financial Year for which you are filing (e.g., 2026-27).
• If you have an LUT from the previous year, you can upload a copy of the acknowledgment, though this is optional.

Step 3: Fill the Undertaking

The screen will display three mandatory checkboxes. By checking them, you agree that:

1. You will complete the export of goods within 3 months of the invoice date (or 1 year for services).
2. You will observe all GST laws.
3. You will pay the tax with interest (18%) if the export is not completed in time.

Step 4: Add Witnesses

You must provide the names, occupations, and addresses of two independent witnesses. Tip: These can be your employees, family members, or colleagues. The portal does not require their digital signatures; just their details.

Step 5: Sign and Submit

• Select the name of the Primary Authorized Signatory.
• Enter the Place.
• Click Sign and Submit with DSC (Digital Signature Certificate) if you are a Company/LLP.
• Click Sign and Submit with EVC (OTP-based) if you are a Proprietorship or Partnership.

Once submitted, the portal instantly generates an acknowledgment (ARN). You should download this ARN and keep it as part of your export documentation.

The Validity Trap: When to File?

A common mistake is forgetting that an LUT expires on March 31 every year. If you issue an export invoice on April 2 without having filed the LUT for the new financial year, that invoice technically becomes "tax-payable." To stay compliant, always file your fresh LUT in the last week of March for the upcoming financial year.

The Consequence of Failing to Export

If you file an LUT but fail to export the goods or receive the foreign currency within the deadlines:

• For Goods: You have 3 months from the invoice date to ship them.
• For Services: You have 1 year from the invoice date to receive the foreign currency (Bank Realization Certificate).

If you miss these deadlines, the LUT for that specific invoice is cancelled. You must pay the IGST on that invoice with 18% interest. If you don't pay, your LUT facility for future exports will be suspended.

Common Mistakes Beginners Make

1. Filing LUT after the Invoice Date: Issuing an invoice dated May 10 but filing the LUT on May 15. Legally, the May 10 invoice is not covered by the LUT. Always file the LUT before the first export of the year.
2. Missing Witness Details: Leaving the witness section incomplete or providing incorrect addresses. While the portal accepts the data, mismatches can trigger ASMT-10 notices during annual audits.
3. Not Mentioning LUT on Invoices: Even if you have an LUT, your export invoice must contain the mandatory phrase: "Supply meant for export under Letter of Undertaking without payment of integrated tax." If this phrase is missing, the invoice is technically invalid for zero-rating.

Conclusion

Filing a Letter of Undertaking is the single most effective way for exporters to protect their liquidity. By spending 10 minutes on the portal once a year, you avoid the administrative nightmare of paying tax in cash and chasing the government for refunds. As India pivots towards being a global export hub in 2026, ensure your LUT is filed before April 1 to maintain a seamless, tax-free global trade presence.