Free to obtain, quick to file — and the basis of the 45-day payment rule your buyers are now bound by.
Udyam registration is free, takes minutes, and is the most under-used business registration in India. It is self-declared on the Udyam portal against your PAN, Aadhaar and GSTIN, with investment and turnover figures pulled automatically from income tax and GST data. What makes it worth doing is not the certificate — it is the payment protection and the priority lending that follow.
Classification limits
An enterprise is classified as micro, small or medium on a composite criterion: both the investment in plant, machinery or equipment and the turnover must be within the limit for that category. The limits were revised with effect from 1 April 2025:
Category
Investment in plant & machinery
Annual turnover
Micro
Up to ₹2.5 crore
Up to ₹10 crore
Small
Up to ₹25 crore
Up to ₹100 crore
Medium
Up to ₹125 crore
Up to ₹500 crore
Export turnover is excluded when computing turnover for classification, which materially helps Chennai exporters stay within a lower category.
Section 43B(h) is the reason your buyers now ask for your Udyam number. A buyer who does not pay a registered micro or small enterprise within 45 days — or within the agreed period, capped at 45 days — cannot claim that expense as a deduction in the year of accrual. The deduction is deferred to the year of actual payment. This has changed payment behaviour among corporate buyers more than any earlier MSME provision, and it only applies if you are registered.
What registration gets you
Delayed payment protection under the MSMED Act, with the right to approach the MSME Samadhaan portal and the Facilitation Council, plus compound interest at three times the RBI bank rate on overdue amounts
Priority sector lending and collateral-free credit under the CGTMSE guarantee scheme
Interest subvention and lower processing charges on several bank products
Public procurement preference — exemption from earnest money deposit, and a share of central procurement reserved for micro and small enterprises
Subsidies on ISO certification, bar code registration, technology upgradation and patent filing under various central and Tamil Nadu state schemes
Electricity and stamp duty concessions under Tamil Nadu MSME policy for eligible units
How to register
Aadhaar of the promoter. Proprietor for a proprietorship; managing partner for a firm; karta for a HUF; authorised signatory with the organisation's PAN for a company, LLP, society or trust.
PAN and GSTIN linked. The portal validates both and pulls investment and turnover data from the income tax and GST systems automatically.
Enterprise details. Activity type, NIC codes for each activity, employee count, bank particulars and the address of every unit.
Certificate. The Udyam Registration Number and e-certificate are generated immediately, with a permanent QR code.
Things that go wrong
Wrong NIC code. If your NIC code says trading and your buyer's tender requires manufacturing, the certificate fails the check. Traders are eligible for Udyam registration but only for priority sector lending purposes, not for the full range of manufacturing benefits.
Multiple registrations. One enterprise gets one Udyam number covering all its activities and branches. Registering the same PAN twice invites a mismatch that has to be corrected later.
Not updating. The registration must be updated with current details annually. Failure to update can suspend the status.
Old Udyog Aadhaar. Udyog Aadhaar memoranda ceased to be valid; anyone still relying on one needs a fresh Udyam registration.
If you are chasing overdue receivables from corporate buyers, registration plus a properly documented invoice trail is what makes the Samadhaan route usable — and the invoice trail is a bookkeeping question as much as a legal one.
Frequently asked questions
Yes. There is no government fee on the official Udyam portal, and no document upload is required because the data is pulled from PAN, GST and income tax records. Sites charging a fee for a certificate are private intermediaries, not the government.
Yes. Retail and wholesale traders were brought within Udyam registration, but the benefit is restricted to priority sector lending. The wider MSME benefits including delayed payment protection under the MSMED Act operate for manufacturing and service enterprises.
It does not expire, but the details must be updated annually from income tax and GST records. If the update is not done, the registration can be suspended, and a suspended registration is treated as no registration by buyers running vendor checks.
If you are a registered micro or small enterprise, you can file on the MSME Samadhaan portal against the buyer, which refers the matter to the Micro and Small Enterprises Facilitation Council. Interest runs at three times the RBI bank rate, compounded monthly, and the buyer separately loses the income tax deduction for that expense until it is paid. Keep the purchase order, invoice and delivery proof; the case is only as strong as the documentation.