Does H1B transfer require Visa stamping

[vins1]

I have valid H1B Visa stamping until 2021 with employer A. If another employer (say company B) applies for my 797 and it's approved.

1) Do I need a visa stamp with employer B to enter the US to work on a daily basis?

2) Can I use approved 797 with existing H1B stamp which is valid till 2021, until the current H1B stamp expires?

3) Once the 797 is approved and I decide to start work at the new employer, do I mention this at the border on the first day and get an updated I-94 for company B?

4) I have a Nexus card, so I assume I have to update my change of employer with them as well.

I am currently on PR in Canada.

 

[21Goose]

No, if you already have a valid H1B visa, you will not need a new one. CBP will update the company name on their end but your visa remains valid if you have a valid I797 along with it.

I don't know the answers to your other questions.

 

[harirajmohan]

I have valid H1B Visa stamping until 2021 with employer A. If another employer (say company B) applies for my 797 and it's approved.

1) Do I need a visa stamp with employer B to enter the US to work on a daily basis?

2) Can I use approved 797 with existing H1B stamp which is valid till 2021, until the current H1B stamp expires?

3) Once the 797 is approved and I decide to start work at the new employer, do I mention this at the border on the first day and get an updated I-94 for company B?

4) I have a Nexus card, so I assume I have to update my change of employer with them as well.

I am currently on PR in Canada.

1. Legally not required provided you received B's I797 approval with I94 printed at the bottom. But there is a catch - if cbp notices then they will start asking why you have not stamped for new company - you cant really do this for long without stamping for new company as some or the other officer insists on it as commuting frequently creates more opportunities to get scrutinized.
2. Yes still officer can ask on it but they do admit you even if he/she asks.
3. No. What you should do is that you staple the I94 for new company in the passport which will show you are requesting admission for new company. if they ask then tell that you are with company B.
4. No. You update the nexus during Important updates such as citizenship change/addition.