My now husband, UK Citizen, entered the US on a K-1 visa, in June 2024. We quickly learned it was not so easy to establish him a bank account - as others have mentioned the bank wanted proof of US residency, and since technically the K-1 visa is a non-immigrant visa we had to over explain, having a relationship with a banker helped a ton here. In order to finally get him an account opened we needed a utility bill in his name (internet was the easiest to get in his name) and a social security number for him.
Prior to my husband entering the US, I had added him as an authorized user on my AMEX by calling in and providing his foreign passport number as the identification number. When he received his US SSN we then faxed that to AMEX, and we were surprised that the “opening date of first account” in regards to his credit score dated back to when I first added him over a year ago. Good luck!