I've been in US on H1B past 8 years, Last year I am changed my status to H4 to obtain EAD. I am on H4 with EAD which is good until July 2020.

I currently have a Full time job and need to travel Tijuana for work for a week.

1) Do I need stamping if travelling to mexico? My last stamping was on H1 and that expired in 2016.

2) Can I go to Mexico for H4 stamping? If so, Should I carry a letter from my company?

Please help... Thanks in advance.