Keep in mind that almost always in HK, banks are veeeeeeeery old fashioned, so you need to be prepared, like actually prepared with all the relevant docs to have any form of success with them.
you need a solid business plan and something that prove that you will have ties to the country or the mainland (suppliers, factories, local companies....etc). +1 If you have some powerpoint presentations to make the eyes of you banker sparkle. +2 if you bring a well dressed local translator that speak Cantonese with you, you won't really need it since alot people in HK speak English well, but bringing a translator with you is always a good idea, since he/she can act as your secretary too which makes you look extra professional in front of the banker.
For me personally, I don't really use a lot of banks in HK anymore, I mostly utilize Asian EMIs and have couple of banks as a backup, but most of my banking is done outside HK.
with that in mind there are good options in HK:
DBS Bank in HK. Assuming the UBO of the company is resident outside HK, his company will fall under "
the special company" category with DBS, meaning that he need to have a minimum 10k HKD to be able to open an account with them (in reality, having 50k+ is advice to have a better success chances, but it can be done with the minimum deposit, if you have a good business plan and the UBO did the above tips that I told you about)
Bank of China. this bank is a hit or miss, depending on the branch that you go to, some are very good, some are meh, none of them are bad tbh, but some branches are better than others. Again, you will need a good business plan, and a deposit of 50k or so (I don't remember the exact numbers). All in all, BOC was one of the easiest bank that I've dealt with in HK.
OCBC singapore. One of the best banks that I've dealt with in Singapore and in Asia overall. you can open a bank account with them for your HK company with relative ease. All you will need is 30k as minimum deposit (the more the better, and If you could throw an extra 10k at a CD or similar investment vehicles, this will do wonders) and a solid business plan as mentioned above.
there are others like HSBC (I hate that bank) and the other international banks, but I always prefer dealing with local banks and so these are the banks that I've personally dealt with.
Keep in mind that run of the mill shelf companies and the likes are better be kept at the trash, because in 2021 and beyond, you need to make sure that you do things right and cross your t's and dot your I's before going offshore, if not, you better stay at home and do things locally to avoid any future frustrations that you will 100% face if you don't do things properly.
good luck to you and your partner!