I have got a stamped H1b visa. I have not travelled yet. Can I apply directly to other companies to work in US?

I have got a stamped H1b visa. I have not travelled yet from current company. Can I apply directly to other companies to work in US using the same H1b visa?

No, you can’t use the same visa. COmpany must file H1B Transfer

The good thing is you dont have to go though the H-1B cap again. Your new company can file a non-cap H-1B petition and get the H-1B transferred.