If you export goods or services, or supply to an SEZ, you’ve probably heard this line from someone in accounts: “LUT file karni hai.” And they’re not wrong.
A Letter of Undertaking (LUT) helps eligible exporters make zero-rated supplies without paying IGST upfront, which protects cash flow. Instead of paying IGST and waiting for a refund, you furnish LUT in Form GST RFD-11 on the GST portal before you start exports for the financial year.
Most exporters lose time here for two reasons. First, they wait until the first export invoice is ready and then rush. Second, they get stuck on small portal details like witness fields, file upload, or choosing the correct financial year.
This guide is written to keep it simple, practical, and fast, so your LUT gets filed smoothly and your exports don’t get blocked.
What is LUT in GST and why exporters use it
LUT stands for Letter of Undertaking. Under GST export rules, exporters can export under a bond or LUT without payment of IGST, subject to conditions. Rule 96A lays down the bond/LUT mechanism for exports without IGST.
The usual business reason to file LUT is cash flow.
When you pay IGST on exports, money goes out first and comes back later through refund processing. LUT helps you avoid that upfront IGST payment for eligible zero-rated supplies, so working capital stays free.
CBIC issued clarifications and procedures for LUT/bond for exports through circulars, and over time the LUT facility has been made widely available for exporters under the rule framework.
Who should file LUT in 2026
You should plan to file LUT if you are GST-registered and you make zero-rated supplies such as:
Exports of goods outside India, exports of services, or supplies to SEZ units/developers (as applicable for zero-rated supply treatment).
The GST portal guidance clearly states that registered taxpayers who have zero-rated supply of goods or services have to furnish LUT in Form GST RFD-11 on the GST portal before affecting such supply.
That one line is the most important practical rule.
If you are going to export in a financial year, file the LUT before you raise the first export invoice of that year. That’s the easiest way to stay worry-free.
When to file LUT and how long it stays valid
LUT is filed for a financial year. Most guidance and compliance practice treat it as valid for one FY and then you file again for the next FY.
There’s also a practical “industry deadline” everyone follows.
Many professionals file LUT for the new FY by 31 March so exports from 1 April can start smoothly without portal dependency or last-minute issues. Recent coverage around FY 2026–27 LUT enablement also recommends filing on or before 31 March 2026 for smooth exports starting 1 April.
So the clean workflow is:
File LUT at year end or at the start of the year, then export freely under LUT conditions through the FY.
What you need before you start the LUT filing
You don’t need a heavy document set, but you do need readiness.
Keep your GST login active and ensure the authorized signatory can access OTP/DSC as required. The portal process requires you to fill details and submit with EVC/DSC depending on entity setup.
Also keep basic details handy: business name, address, GSTIN, and two witness details. The GST portal user guide shows that you must enter details of two independent and reliable witnesses in the RFD-11 screen.
If you filed LUT last year, keep a copy ready because the portal allows uploading previous LUT (as per the user guide steps).
7 steps to file GST LUT online on the GST portal in 2026
This is the exact sequence that works cleanly.
Step 1 – Login to GST portal
Login using your GST credentials. Keep your phone/email accessible for OTP.
Step 2 – Open the LUT option
Navigate to the LUT filing function:
Services → User Services → Furnish Letter of Undertaking (LUT)
This is the correct menu path as shown in the official GST portal guidance.
Step 3 – Select the correct financial year
On the RFD-11 screen, select the financial year for which you are applying LUT. The portal guide explicitly shows selecting “LUT Applied for Financial Year” from the dropdown.
This is where people make an avoidable mistake by selecting the old FY. Double-check before moving ahead.
Step 4 – Upload previous LUT if asked
The portal allows uploading the previous LUT. It also specifies file type and size limits (PDF or JPEG and size limit), so keep a small, clear file ready.
If you don’t have the previous LUT file, don’t panic. Many taxpayers still proceed based on portal requirements and current year declarations, but uploading previous LUT can reduce confusion and supports continuity where asked.
Step 5 – Tick declarations carefully
The declarations are not “just checkboxes.” They are your undertaking regarding conditions of export under LUT, so tick them carefully after reading.
Step 6 – Fill two witness details
Enter the name, address, and occupation for two witnesses. This step is shown in the portal guide and is mandatory in the RFD-11 interface.
Keep it simple and accurate. Use real individuals and correct addresses.
Step 7 – Submit using EVC or DSC and save ARN
Complete submission and save the acknowledgement reference. Your ARN acts as the proof of successful submission.
Once LUT is furnished, you should be able to export under LUT for that FY, subject to compliance conditions.
What happens if you don’t file LUT and still export
If LUT is not furnished, many exporters choose the other route: pay IGST on exports and then claim refund. That works, but it can lock cash flow for weeks or months depending on processing and documentation readiness.
This is why most growing exporters prefer filing LUT early and keeping exports smooth from day one.
Common LUT filing mistakes that delay exports
These are the problems BizSetups sees most often. I’m keeping this short and practical.
The first is selecting the wrong financial year on RFD-11. That creates confusion later when your invoices are in a new FY but LUT is filed for an old one.
The second is missing witness details or entering incomplete witness address fields. The portal requires witness fields in the LUT form flow.
The third is waiting until the first export shipment date. If there’s portal load, OTP issues, or signatory unavailability, the shipment gets delayed for a silly reason.
The fourth is assuming “LUT has a fixed legal last date.” In practice, LUT must be furnished before making zero-rated supply for that FY, and many people aim for 31 March as a practical cutoff to avoid disruption from 1 April.
A simple LUT routine for FY 2026–27 that keeps you stress-free
If you want this to feel effortless, use this yearly rhythm:
At the end of March, file LUT for the next FY. Then in April, do your first export invoice without IGST payment under LUT.
If you’re an agency or service exporter, do it the same way. File LUT first, export services next.
This one habit prevents last-minute chaos and avoids cash being blocked.
Get LUT filed correctly with BizSetups
If you want LUT filing handled quickly and cleanly, BizSetups can support you with:
Correct FY selection, portal filing, witness field guidance, and submission support so your export operations don’t stop due to avoidable compliance gaps.
We serve exporters across India, and for faster coordination you can also connect with our teams in Noida and Gurugram.
Share your GSTIN and the FY you want to file LUT for, and we’ll guide the fastest way to complete RFD-11.
FAQ | Steps to File GST LUT Online
1) What is the form used for LUT in GST
LUT is furnished online in Form GST RFD-11 on the GST portal.
2) Who needs to file LUT
Registered taxpayers making zero-rated supply of goods or services should furnish LUT on the GST portal before affecting such supply.
3) Where do I file LUT on the GST portal
Login and go to Services → User Services → Furnish Letter of Undertaking (LUT).
4) Is LUT valid for one financial year
Common compliance practice and guidance treat LUT as valid for one FY, and exporters generally file it again for the next FY.
5) When should I file LUT for FY 2026–27
LUT should be furnished before making zero-rated supply for the FY. Many taxpayers file it on or before 31 March 2026 so exports can start smoothly from 1 April.
6) Why are witness details required in LUT filing
The GST portal LUT form flow includes fields for two witnesses and requires their details to be entered before submission.
