It's April 30, 2026 — the practical deadline to file your Letter of Undertaking for FY 2026-27. Without a fresh LUT, your next zero-rated export invoice forces you to either pay IGST (and chase the refund for months) or export under bond. Both are avoidable in the next 30 minutes. This is the exact checklist we walk our exporter clients through, with the rejection traps that catch people every year.
30 min
Time to file LUT end-to-end on the GST portal
3 days
Deemed-approval window if officer takes no action
2
Witnesses required (with PAN, address, occupation)
5
Most common reasons LUTs get rejected
## What an LUT actually does
A Letter of Undertaking (Form GST RFD-11) is your written declaration that you'll fulfil the conditions for exporting goods or services without paying IGST. It's required under Rule 96A of the CGST Rules. Once accepted, every export invoice you issue in FY 2026-27 can be zero-rated — no IGST on the invoice, no refund cycle to chase. Without an LUT in place, you have two worse options: pay IGST and apply for a refund (typical wait: 60-90 days, sometimes longer), or execute a bond with bank guarantee (paperwork-heavy, banker time, fees).
The real deadline: The CGST Act technically wants the LUT before the first export invoice of the financial year. In practice, the GST portal allows filing through April but flags exports made before LUT acceptance as ineligible for the zero-rating route. File before any FY 2026-27 export goes out.
## The 5 most common rejection reasons
These are the ones we see every April across 30+ exporter clients. Each is preventable in under 5 minutes if you know to check.
FY
Wrong financial year selected
The portal opens to the current FY by default. If you're filing in late March for the upcoming year, you must manually switch to FY 2026-27. Filing under FY 2025-26 by accident submits a duplicate of last year's LUT and gets rejected.
PAN
Name mismatch between PAN and GSTIN
If your trade name on PAN reads "ABC Exports Pvt Ltd" and on GSTIN reads "ABC Exports Private Limited", the system flags it. Fix the GSTIN registration first via core amendment; LUT will reject otherwise.
W
Witness details incomplete or fake
"Friend's name + random PAN" doesn't pass. Officers do verify a sample. Use real witnesses — your CA, your office admin, your banker — with valid PAN, full address, occupation. Both witnesses must be Indian residents.
DSC
Expired DSC or unauthorised signatory
If your authorised signatory's DSC expired in March, renew before filing. If the signatory listed on GSTIN doesn't match the one signing the LUT, the portal rejects on submit.
IEC
Missing or stale IEC linkage
Your IEC must be linked on the GST portal under "Profile". If you got a new IEC in the last year and never updated GSTIN, the LUT submission fails. Check Profile > Update before filing.
## The 30-minute walkthrough
Block 30 minutes. Have your DSC, IEC, and two witness names handy.
1
Login and verify pre-requisites (5 min)
gst.gov.in. Login with your GSTIN. Hover over Services > User Services > "Furnish Letter of Undertaking (LUT)". Before clicking, open Profile > Authorised Signatory in another tab — confirm the active signatory's DSC is valid until at least March 2027. Confirm Profile > Update Bank Account shows your active export bank account. Confirm IEC field is populated under Profile.
2
Open RFD-11 and switch to FY 2026-27 (1 min)
Click "Furnish Letter of Undertaking (LUT)". The form is GST RFD-11. The "LUT applied for Financial Year" dropdown defaults to the current year — manually select 2026-27. This is the single most-skipped check.
3
(Optional) Upload previous LUT (3 min)
If you have last year's LUT acceptance order as a PDF, upload it under "Documents". Not mandatory, but speeds up officer approval. Skip if you don't have it — the system doesn't require it.
4
Self-declarations (3 min)
Three checkboxes confirm: (1) you'll complete export within 3 months of invoice date, (2) you'll abide by GST law on export, (3) you'll pay IGST + interest if you fail conditions. Read them; tick all three. The portal won't let you proceed otherwise.
5
Witness details (5 min)
Two witnesses. For each: full name, PAN, full address with PIN, occupation. The PAN is verified against the IT database in real time — wrong PAN throws an immediate error. Don't paste your own PAN; you can't be your own witness.
6
Place, date, signatory selection (2 min)
Place: city of execution (e.g., "Mumbai"). Date: today's date. Pick the authorised signatory from the dropdown — this populates from your GSTIN registration. If the right person isn't listed, fix the registration first before continuing.
7
Save, preview, submit (5 min)
Save once to generate a draft. Preview as PDF. Re-read the witness names and PAN — typos here are the #1 reject reason. Then "Submit with DSC" or "Submit with EVC". DSC is faster but requires the emSigner running. EVC sends an OTP to the registered email and mobile.
8
Capture the ARN and download the receipt (1 min)
On submit, the portal returns an ARN (Application Reference Number) starting with AD followed by date and number. Download the acknowledgement PDF. Save both ARN and PDF in your Drive folder for the year. You'll need them if your LUT is queried.
9
Wait for status (5 min check, then asynchronous)
Check Services > User Services > View My Submitted LUTs. Status will be "Submitted" initially. If the officer takes no action in 3 working days, it auto-flips to "Deemed Approved". If the officer raises a query, you'll get a notice on email — respond within the timeline given.
## Post-filing software updates exporters always forget
This is the part most LUT articles skip. Once your LUT is accepted, three things in your billing stack need to update.
- Export invoice template: The footer should now read "LUT No: [your ARN] dated [LUT submission date]" alongside the existing "Supply meant for export under LUT without payment of IGST" annotation. Tally users: edit the invoice voucher template under Display > Statutory > GST > Configure. Zoho Books users: Settings > Templates > Invoices > Edit > Footer.
- Tax type on export invoices: Every export invoice for FY 2026-27 should have the GST type set to "Without Payment of Tax" or equivalent. In Tally, this is configured at ledger level for the buyer. In Zoho Books, set the customer's GST treatment to "Overseas".
- e-Invoicing for exports: Exports above the e-invoice threshold (₹5 Cr AATO from April 2026) require IRN. The export type field in the IRP payload must be set correctly: "EXPWP" (with payment) or "EXPWOP" (without payment, i.e., under LUT). Most ERPs default to EXPWP — change to EXPWOP for LUT exports.
- Shipping bill cross-reference: Update your CHA's checklist to include the LUT ARN. Customs systems cross-reference LUT status with shipping bills for IGST drawback eligibility. Mismatch causes drawback delays.
- Refund tracking spreadsheet: If you've been chasing IGST refunds from FY 2025-26 because you didn't have an LUT then, separate them from FY 2026-27 zero-rated exports in your tracker. Different rules, different forms (RFD-01 vs RFD-11A).
- Bank advice format: Some authorised dealers (banks) ask for the LUT acknowledgement when releasing inward remittances. Save the LUT PDF in a shared folder accessible to your banker.
- SEZ supplies: Supplies to SEZ units (not just exports out of India) also fall under zero-rating with LUT. If you sell to SEZ-registered buyers, the same LUT covers it — but make sure your invoice GSTIN-state combination correctly identifies the SEZ unit.
## When NOT to file an LUT
Three cases where an LUT is the wrong choice or unnecessary:
-
You don't actually export. If your "exports" are services to an Indian buyer's overseas branch where the contract is with the Indian entity, that's not an export. It's a domestic supply. LUT doesn't apply; the supply is taxable at standard rates.
-
You can't meet the export-realisation timeline. LUT requires you to receive payment in convertible foreign exchange within 12 months for goods (1 year) or services (1 year). If you regularly miss this — say, you're a small services exporter with slow-paying clients — you may be better off paying IGST and claiming refund after realisation.
-
You're an SEZ unit yourself supplying to a DTA. Different rules apply. Talk to your CA before assuming LUT covers you.
## Real example — a Surat textile exporter, 24 staff
Client: a Surat-based textile exporter shipping to Dubai and Lagos. FY 2025-26 turnover ~₹14 Cr. Files LUT every year, but every year there's a different glitch.
What we found this April:
- Their authorised signatory's DSC expired on April 18 — invisible to them until they hit submit and got the error.
- Their IEC was renewed in November 2025 with a slightly different format (extra zero) — never reflected on the GST portal.
- They were planning to use their dispatch manager as a witness — same person was already an authorised signatory (not allowed).
We renewed the DSC in 90 minutes (online via eMudhra), updated IEC linkage on the GST portal, and got two genuine third-party witnesses (their CA and their banker). LUT submitted at 4:12pm; deemed approved at 11am two working days later.
Their first export invoice for FY 2026-27 went out on April 22 with no IGST and the LUT ARN in the footer. The CHA's drawback claim cleared in 9 days — versus 47 days for last year when the LUT had been queried.
For ongoing reading, [r/IndiaBusiness](https://www.reddit.com/r/IndiaBusiness/) has running threads every April from frustrated exporters who hit the rejection traps. Worth scanning before you file.
## FAQ
### Can I file LUT after April 30?
Yes — the GST portal accepts LUT applications throughout the year. But any export invoice issued before LUT acceptance is at risk: the supply is technically subject to IGST until the LUT covers you. File before your first FY 2026-27 export.
### Is LUT the same as a bond?
No. An LUT is a self-declaration with two witnesses; no bank guarantee, no money tied up. A bond is required for exporters who don't qualify for LUT (e.g., past prosecution under tax laws involving evasion above ₹2.5 Cr) and requires a bank guarantee of 15% of the bond value.
### What is "deemed approval"?
If a tax officer doesn't take any action on your LUT application within 3 working days of submission, the portal auto-marks it as "Deemed Approved". Your LUT is valid from that point, even without an explicit acceptance order.
### Does LUT expire?
Yes, every financial year. An LUT filed for FY 2026-27 is valid only for exports made between April 1, 2026 and March 31, 2027. You must file fresh for FY 2027-28.
### Can my employee be a witness?
The CGST Rules don't explicitly prohibit it, but in practice officers prefer two unrelated parties — typically your CA, your banker, or another professional advisor. A subordinate employee witnessing their own employer's LUT looks weak.
### What happens if my LUT is rejected?
You receive a rejection notice with the reason on email and on the portal. You can either fix the issue and re-file (most common) or appeal. Don't issue export invoices in the gap — those will be treated as taxable supplies subject to IGST.
### Is LUT needed for service exports too?
Yes. The CGST Act treats export of goods and export of services equivalently for zero-rating. The only difference is the realisation timeline: 12 months from the date of issue of invoice. Software exporters, freelance designers, content writers selling to overseas clients all need an LUT.
Want Your Export Billing Software Updated for FY27?
We update Tally Prime, Zoho Books, BUSY, or your custom invoicing app with the FY 2026-27 LUT details — invoice templates, IRP export-type flags, customer GST treatment, drawback tracking. Typical scope: 2-4 hours, fixed fee. Suitable for goods and services exporters with up to ₹50 Cr turnover. Includes a 15-min demo call.
Book a Software Update Call
Email contact@softechinfra.com if you want our LUT-rejection checklist sent over before you start the filing — saves another 10 minutes of debugging.