Can I start working on October 1st with the receipt of a new H1-b visa?

I’m in USA with a tourist visa. I got the sponsor for a work visa and we filled all the documents for the change of status. I recieved the H1-b receipt 3 almost 4 months ago and I still waiting for the approval. I know that the fiscal year starts on October 1st. Does it mean that I can start working that day? Or do I have to wait for the visa approval?

You cannot work until Visa is approved. That will be illegal.

Are you sure? I though the same, but my attorney told me the other day that I can…

Your attorney talks on behalf of your employer, and not on your behalf. It is you who will be at risk in case if USCIS discovers that you are working on visitors Visa.

Ok, thank you for the information!