Working on L1 when H1 has been approved

[meenu]

My friend's H1 visa has been approved in Oct.He is still working on L1 visa with his previous company.From December he plans to join a new company on H1. Is it legal to continue working on L1 when his H1 has been approved?Should he join the new company immediately or can he wait for a month?
Please help.

[meenu]

any help is welcome..

[meenu]

For information of others my friend found out from attorney that my friend's current status is L1 as his campany had filed for L1 extension after H1 approval date.

[gc_possible]

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