My H1B Visa approval notice in Jan 2018 but stamping is not yet done

My H1B Visa approval notice in Jan 2018 but stamping is not yet done because my employer is looking for client change then I’ll have to go for H1B and LCA amendments. Now my visa is about to expire as it was approved for 1 year only.

I would like to know what happens if my employer is unable to get alternate client letter and relevant details before the visa expiration date.

Pleased advise.

The will have to refile your H1 under cap-exempt category, with new client details etc. instead of amendment.