If filling out name in w9 for the first time. Should they put (1) just first and last name, or (2) first , middle initial, last name, or (3) full name spelled?

[rjs]

It doesn't matter. They should put their name on the W-9 the way they want the payer to put it on checks and 1099 forms.

You are talking about Form W-9 that they use to provide their tax ID number (SSN or EIN) to a client or someone else (but not an employer) who is going to make payments to them, is that right? Who are "they," and what is their connection to you?

[9corners]

Thanks for your reply!

"They" is my child.

[Critter-3]

READ the W-9 instructions ... there is one for each line :   https://www.irs.gov/pub/irs-pdf/fw9.pdf

[Carl]

While it's not a requirement in writing anywhere I'm aware of, if you enter the individual's name just as it appears on their social security card, you'll be fine.