I'm USA-based. They have a download packet and you just need to follow their checklist. It can be difficult because they refer to documents that are not commonly used in the USA, such as a "Certificate of Incumbency".

They now annually require you to submit roughly the same documents. I've had problems in the past because I upload ALL of the requested the documents,and then wait MONTHS with no feedback. Every time you log in you get a message saying "Upload your documents or your account faces suspension", which can be unnerving. If you call, they say, "Oh, don't worry, someone will contact you if there is a problem."

I would usually visit HK at the tail end of the "deadline", and would go to a branch to try to get any questions resolved. (It's usually a matter of trying to find the proper US documents that roughly equate to what they want.) One time it is really annoying because last minute, while I was in HK, they asked for a document that needed to be notarized. Of course, HK has notaries. But it is much different than in the USA. Here, a notary basically just certifies that it was you that signed the document; a sort of identity confirmation. But in HK, the notary is much more "intrusive". They wanted to read all the papers, and had questions about them. I needed to sign as the President of the company, and instead of just confirming my identity, they needed proof that I was an officer of the company! And it was pretty expensive. Here notary services are $10 at the UPS store. I don't remember exactly, but it was maybe $1000HKD!

With all that said, I will say that for the most part HSBC works great. It is very helpful to have the account there. It saves on wire transfer fees. It makes payments to factories very fast. Paperwork requirements aside, I am satisfied with HSBC.