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The Annual March 31 Deadline Every Exporter Must Know
If you run an IT agency, provide software development services, or export consulting from India, the Letter of Undertaking (LUT) is your most critical tax document.
Under Section 16 of the Integrated Goods and Services Tax (IGST) Act, exports of services are classified as Zero-Rated Supplies. This means you are legally entitled to bill international clients without paying 18 percent GST, provided you have filed a valid LUT before issuing your invoices.
Here is the catch that trips up hundreds of Indian tech companies every year: A Letter of Undertaking is valid for exactly one financial year. It expires on March 31. If you continue invoicing overseas clients on or after April 1 without renewing your LUT for Financial Year 2026-27, your exports are legally treated as non-compliant, leaving you exposed to 18 percent IGST tax demands, interest penalties, and working capital lockups.
In this guide, we walk you through the exact step-by-step process of filing Form GST RFD-11 on the GST portal, avoiding common witness mistakes, and maintaining flawless invoicing compliance.
What Is Form GST RFD-11 and Who Must File It?
Form GST RFD-11 is the statutory application form submitted on the GST portal to furnish a Letter of Undertaking for export of goods or services without payment of integrated tax.
You must file an LUT renewal if you meet all of the following conditions:
- You are registered under GST in India as a Proprietorship, Partnership, LLP, or Private Limited Company.
- You export services (software development, web design, digital marketing, consulting, SaaS) or physical goods to clients located outside India.
- You receive payments in convertible foreign exchange (such as USD, EUR, GBP, AUD, or CAD) through authorized banking channels.
- You have not been prosecuted for tax evasion exceeding 250 lakh rupees under the CGST or IGST Act.
Step-by-Step: How to File Your GST LUT for FY 2026-27 Online
Filing an LUT takes less than 10 minutes on the government GST portal (gst.gov.in). Follow these verified steps:
Step 1: Log In and Navigate to LUT Services
Log in to the official GST portal using your credentials. From the top navigation menu, click on Services > User Services > Furnish Letter of Undertaking (LUT).
Step 2: Select Financial Year 2026-27
In the dropdown menu labeled “LUT applied for financial year”, select 2026-2027. If you filed an LUT for the previous financial year, enter the Application Reference Number (ARN) of your previous LUT in the designated field.
Step 3: Agree to Statutory Undertaking Checkboxes
You must tick all three mandatory compliance checkboxes:
- To export services or goods without payment of integrated tax within the time limit specified under Section 16 of the IGST Act.
- To observe all the provisions of the GST Acts and rules in respect of export of services or goods.
- To pay the integrated tax along with interest (18 percent per annum) in the event of failure to realize export proceeds in convertible foreign exchange within the period prescribed under FEMA.
Step 4: Enter Details of Two Independent Witnesses
You are required to furnish details of two witnesses. For each witness, you must enter:
- Full Legal Name (as per PAN or Aadhaar).
- Occupation (for example: Accountant, Software Engineer, Business Analyst).
- Complete Residential Address (including street, city, state, and pin code).
Important Note: Witnesses do not receive an OTP or physical verification. However, their physical address must be complete and accurate. You can name trusted team members, professional colleagues, or family members who are adults.
Step 5: Sign and Submit with DSC or EVC
Select the Authorized Signatory from the dropdown. Enter the Place of signing (your registered city). You can sign using:
- Electronic Verification Code (EVC): An OTP sent to the authorized signatory registered mobile number and email. Ideal for Proprietorships, Partnerships, and LLPs.
- Digital Signature Certificate (DSC): Mandatory for Private Limited Companies and Public Limited Companies.
Once verified, the portal instantly generates Form GST RFD-11 with a 15-digit Application Reference Number (ARN). Download the PDF acknowledgment immediately for your tax audit files.
The 4 Costly LUT Mistakes Technology Exporters Make
- Quoting an Expired Previous-Year LUT ARN: Every invoice issued after March 31 must quote the new FY 2026-27 ARN. Billing April export invoices with an expired ARN is a red flag during GST audits.
- Failing to Realize Foreign Remittances Within 9 Months: Under FEMA 23(R) and GST export rules, you must realize foreign exchange within 9 months. If foreign remittance is not realized, your zero-rated LUT status is revoked, and 18 percent IGST becomes payable.
- Missing LUT Declaration on Invoice Header: Every export invoice must carry this mandatory legal text: “SUPPLY MEANT FOR EXPORT OF SERVICES UNDER LETTER OF UNDERTAKING WITHOUT PAYMENT OF INTEGRATED TAX (LUT ARN: [YOUR-NEW-ARN-NUMBER])”.
- Omitting the Correct SAC Code: Using generic or mismatched 6-digit SAC codes (such as 998314 for Software Development or 998361 for Digital Marketing) creates reconciliation discrepancies during refund filings.
Automate LUT Export Invoicing with CodXpert Invoices
Managing multiple currencies, tracking LUT ARN numbers, converting foreign wire totals into legal words, and generating bank FEMA 23(R) export declarations is a headache when done manually in Excel.
CodXpert built its dedicated invoicing software, CodXpert Invoices (https://invoice.codxpert.com/), specifically to automate export compliance for Indian agencies and developers:
- Automatic LUT ARN Locking: Enter your FY 2026-27 ARN once, and it automatically stamps onto every multi-currency invoice PDF.
- 1-Click Bank FEMA 23(R) Declaration Export: Generate pre-filled HDFC and standard bank declaration workbooks matching your realized wire.
- Live Exchange Rate Locking: Fetch statutory reference exchange rates on the date of invoicing for exact GSTR-1 Table 6A reporting.
FAQs (Frequently Asked Questions)
When is the best time to renew the LUT for FY 2026-27?
- The GST portal opens LUT renewal in March. It is best practice to submit your renewal between March 15 and March 31 so your new ARN is active on April 1.
Is there any government fee to file an LUT?
No. Filing Form GST RFD-11 on the government GST portal is completely free.
What happens if I forget to renew and issue an export invoice in April?
- You should file your LUT immediately. While you can apply for condonation of delay with your jurisdictional GST officer, issuing invoices without an active LUT invites scrutiny and potential tax demands.
Never risk an invoice tax dispute again. Generate GST LUT compliant multi-currency export invoices and automated bank-ready foreign remittance declarations in seconds with CodXpert Invoices.
Shadab Alam
Founder of CodXpert • Co-Founder of Anterpreneur & Niagara Print Express
Shadab Alam is an entrepreneur, technology strategist, and the Founder of CodXpert, as well as Co-Founder of Anterpreneur and Niagara Print Express (NPE). With expertise in software engineering, artificial intelligence, SEO, digital transformation, and business strategy, he empowers businesses to innovate, automate processes, and accelerate sustainable growth through modern technology and data-driven solutions.
