The question comes up on nearly every enquiry, and the answer is simpler than it looks: it depends on whose name the document must be signed in.
Individual certificate
A Class 3 individual certificate carries only your name. Use it when you are signing as yourself — filing your own income tax audit, signing as a Chartered Accountant on a clientu2019s behalf, applying for a trademark in your own name, or bidding on a tender as a sole proprietor.
Organization combo certificate
An organisation combo certificate carries both your name and your entityu2019s name, and includes signing plus encryption on one token. Use it when the document is filed on behalf of a company, LLP, firm, trust or society — MCA and ROC filings, GST returns for the entity, EPFO filings, and most e-tender submissions.
The practical test
Look at the portal. If it asks you to register a signatory against an entity, you need an organisation certificate. If it registers you as an individual professional, an individual certificate is correct.
Can one person hold both?
Yes, and many do. A CA might hold an individual certificate for client filings and an organisation certificate for their own firm. They are separate certificates on separate tokens.
Getting it wrong
The portal will reject the filing, not accept it silently. If you are unsure, call before you order — a two-minute conversation avoids a wasted certificate.