Udyam registration looks simple from the outside: Aadhaar, PAN, a few business details, done. In practice the first question a CA gets is not how to register but whose details to use. A partnership, an HUF or a private company does not have an Aadhaar of its own, and the wrong choice at the start is hard to undo later.
This guide takes each type of entity and sets out whose Aadhaar, which PAN and what else the form needs.

The rule behind every case
Udyam registration is filed on the Government's Udyam portal, free of cost. Every registration rests on two things:
1. An Aadhaar number of one named person, verified by OTP on the mobile linked to that Aadhaar.
2. The PAN of the enterprise, and its GSTIN where the business is required to hold GST registration.
The Aadhaar identifies who is filing. The PAN identifies the enterprise, and the portal pulls investment and turnover figures from the income tax and GST data linked to it. Only one Udyam registration is allowed per PAN.
Entity by entity
- Proprietorship: Aadhaar of the proprietor; the proprietor's own PAN
- Partnership firm: Aadhaar of the managing partner; the firm's PAN
- HUF: Aadhaar of the karta; the HUF's PAN
- LLP: Aadhaar of an authorised signatory (designated partner); the LLP's PAN
- Private or public limited company: Aadhaar of an authorised signatory (usually a director); the company's PAN
- Cooperative society, society or trust: Aadhaar of an authorised signatory; the entity's PAN
Where it goes wrong
Proprietorship registered under a business name PAN. A proprietorship has no separate PAN. The registration uses the proprietor's personal PAN, and the business name is entered as the enterprise name. If the client has been filing returns as an individual, that is the PAN that carries the turnover.
Partnership filed with a partner's own PAN. The firm's PAN must be used. A registration under the partner's personal PAN creates an enterprise that the firm's books, returns and GST data do not match, and the classification will be worked out from the wrong figures.
The person with the OTP is not available. The Aadhaar used must be linked to a working mobile number, because the OTP goes there at registration and at every later update. For a company, pick a director who will stay involved. Changing the person later means updating the registration, which again needs an OTP.
Name mismatch. For a proprietorship, the name on Aadhaar and PAN must match closely, or the PAN check fails. Initials, spellings and surnames after marriage are the usual causes.
GSTIN left out. Where the business is required to register under GST, the GSTIN must be entered. A business that is exempt from GST can register without one.
Units and activities
A business with more than one location does not need a second registration. Each plant or office is added as a unit under the same Udyam number. Each activity gets its own NIC code. A firm that manufactures and also trades should list both, with the main activity first.
Retail and wholesale traders can register too. Their registration counts for priority sector lending, but they do not get the delayed payment protection of the MSMED Act, so their buyers are not bound by the 45-day rule for them.
What to collect before you start
For a smooth filing, ask the client for:
- Aadhaar number of the right person, with the linked mobile at hand for the OTP
- PAN of the enterprise, and GSTIN where applicable
- Date of incorporation or commencement of business
- Address of the main office and every unit
- Bank account number and IFSC
- Main activity and any other activities, to choose NIC codes
- Number of employees, split by gender
Investment and turnover need not be typed in. The portal takes them from the ITR and GST data linked to the PAN, which is one more reason to make sure the right PAN is used.
After registration
The certificate shows the classification as micro, small or medium, and it is updated each year from the returns. Address, units, bank details, NIC codes and contact numbers are not. Those stay as entered until someone logs in and changes them, so a yearly look at the certificate saves trouble when the client applies for a loan or a tender.
When the client wants it done for them
Registration on the official portal is free, and most practices handle it in a few minutes once the right details are at hand. Clients who would rather hand over the whole process can apply for Udyam registration here. It is a paid service and is not connected to the Government or the Ministry of MSME.
In short
Before filing, settle two things: whose Aadhaar and which PAN. For a proprietorship, both belong to the proprietor. For every other entity, the PAN is the entity's and the Aadhaar is that of the person authorised to act for it. Get those right and the rest of the form takes care of itself.