How long H1 status is valid without pay checks.

I am on H1B currently looking for a job in USA and I heard that I can still hold H1B status to a maximum of 180days without pay checks. Is this correct? Shall I apply for SSN or wait until job confirmation?

When you are in US on H-1 and not getting paid, you start accumulating “out of status”. Once you have stayed for 180 days like that, you can be banned for 3 years from entering US.

However, you should not take that 180 day limit lightly. If you stay for even 1-2 months, even that can cause serious issues in future (stampings, extensions, GC etc).

Your employer needs to start paying you on H-1 irrespective of whether you are a billable asset or not. You can apply for SSN now. And you already have a job - its with the company that filed H-1 and signed contract with DOL/USCIS to pay you timely.