W-9 or W-8?

I recently received my EAD and SSN (after waiting months..).

I went to Chase bank today to change my ITIN to my SSN. The person I spoke to gave me a W-9 form to fill out, which says it's for "U.S persons". I wasn't sure if I should fill that out, so I left. I went on Chase bank's website and noticed there was also a W-8 form, for "non U.S persons".

Which one are we supposed to fill out? W-9 or W-8?

*if it helps to clarify, the W-8 had other letters after it

Did your banks give you a similar form to fill when changing/updating your SSN?

Thanks for your replies, in advance!

W-9 if you have a SSN and EAD.
You will also be asked to fill it out if you get a job.

Thanks, this really helped!