I went through this in August 2026 as a sole trader in Portugal - no company, no LLC - and my app is now submitted as Paid via Atlassian with partner verification approved. So the short answer to (1) is yes, an individual can. The longer answer has one trap in it that would have cost me weeks, so it is worth writing out.
The gate is Partner Verification, and it comes before the listing. Atlassian’s wording to me was that it “is a prerequisite to uploading any apps on the Marketplace”. It arrives as an ECOHELP ticket with a form embedded in it, not as something you find in the vendor portal.
What the Identity Information form actually asks for, so you can gather it in one sitting: business name, registration number, tax ID and full business address; an explicit “Are you a Sole Proprietor?” (so your case is anticipated, not an exception you have to argue for); and personally your full name, contact email, date of birth and home address.
With no company registration I used my personal tax number (NIF here; PAN would be the equivalent for you) for both the registration number and the tax ID, answered Yes to sole proprietor, and gave my home address as the business address. That was accepted. So on your question (2): a personal tax ID was sufficient and no business registration certificate was asked for.
Atlassian state this is collected for government compliance and sanctions screening, that it is not shown publicly, and that the ticket locks down to the Primary Partner Contact once submitted.
The same ticket also names a “Partner Security Questionnaire”. In my case that turned out to be the Marketplace Security questionnaire already in the vendor portal - its Partner and Partner-Extended tabs are exactly partner-level questions, and trying to open a questionnaire from the ECOHELP ticket returned “not available for this request type”. So do not go hunting for a second one.
Now the part that matters most, and where I would have got it wrong.
Paid via Atlassian means Atlassian pay you, and they act as a US withholding agent. With no W-8 on file the statutory default is 30%. As a non-US individual the form is W-8BEN (not W-8BEN-E, which is for entities). There is no upload field for it anywhere in the vendor portal - you attach it to the ECOHELP ticket.
First thing I would flag: Atlassian told me “a U.S. TIN is required for exemption from tax withholding.” For an individual claiming treaty benefits that is not what the IRS instructions say. The Form W-8BEN instructions let you complete line 6a with a foreign tax identification number from your country of residence instead of an SSN or ITIN for a treaty claim. I put my national tax number there. No ITIN and no Form W-7 - which would otherwise have meant a certified copy of my passport and weeks of waiting. For you that line would be your PAN. Check your own treaty and the current instructions, but do check before you start a W-7.
Second: ask them how they classify the income. They told me Marketplace app sales are business profits under Article 7, not royalties, their reasoning being that the licensee buys a copy to run rather than a right to exploit the IP. Most treaties treat those two very differently, so it is worth having their answer in writing before you fill in line 10, which is the field that actually does the work.
A W-8BEN is valid through 31 December of the third year after you sign it, so diary the expiry. An electronic signature was accepted in my case.
On your third question - a revenue threshold above which formal registration becomes mandatory - I do not know, and I saw nothing on the Atlassian side. I would expect that to be a question about your own country’s rules on when trading requires registration rather than an Atlassian rule, so it is worth an accountant locally rather than a forum answer, mine included.
Usual caveat: one person, one jurisdiction, three weeks ago, and not tax advice. But the sole-trader path does work end to end, and the ITIN point is worth checking before you assume you need one.