Howsoon one can change the company after L1 to H1

[lakkivas]

Hi,

Now I am working for company "A" on L1 in Texas.

I got approval for L1 to H1 as Change of Status recently in JUN 2012 through New jersy company "B".

I am going to join new company "B" on H1 in the mid of October.

Q: I am expecting new offer from Company "C" in October Mid.

If I join company "B" in October mid,How soon I can apply for H1b transfer through company "C" ?

Some of my friends told me that at least we should wait for 1 pay stub from company "B" before joining company "C" and some told me that we can join company "C" as soon as one get H1B(H1b transfer) approval through company "C"

Can you please provide me some information.

Thanks,

Lakshmi