On an H-1B and half my colleagues insist a small side business is fine — what did people actually find out?

I did the version where you find out afterwards. Two small contracts over about eight months, maybe four thousand dollars total, on the basis that a colleague said it was fine. When my paperwork came up later I ended up disclosing it and paying for several hours of attorney time to explain it properly, which cost more than the contracts had paid and took two months of sleeping badly. It resolved. I would pay for the consult first every single time now.

The distinction that kept coming up when I looked into it was between owning something and working for it. Holding an investment, or owning a share of a company somebody else runs, is a very different question from you personally doing billable design work and being paid for it. I set up an entity and then did nothing with it for two years on my attorney's instruction, which felt absurd but meant there was nothing to explain later. If your plan involves you doing the work and someone paying you for it, do not take comfort from the ownership half of that distinction.

The only thing that ended the argument for me was paying an immigration attorney for a single consultation and getting the answer in writing with my specific facts in it. Mine was a flat fee for an hour and it was the best money I spent that year, because what I had been told at work was confidently wrong in both directions. The general shape of what I was told is that your status authorises work for the petitioning employer in the role on the petition, and paid work for anybody else is a separate question entirely — but the details are where people get hurt, and my details are not your details. Get your own opinion, in writing, before any money moves.

Mild disagreement with the flat never-do-anything answers you will get in here. The blanket no is not accurate either — there are legitimate routes that involve separate authorisation, and people do hold more than one authorised position. But every one of those routes involves paperwork filed before the work starts, not a favour for a friend that you sort out afterwards. So the practical answer lands in the same place: your own attorney, your own facts, before the first invoice.

Your employer saying they do not mind answers an employment contract question, not a status question. Those are two different systems and only one of them can take your status away. Treat their permission as necessary and nowhere near sufficient.

One practical thing while you wait for a real answer: the unpaid parts of building a side business are usually a much safer place to put those five hours anyway. Learning the craft, writing, building a portfolio of your own work. If you eventually get a green light you are a year ahead, and if you don't, you have lost nothing but time you enjoyed.