1099 NEC Filing Deadling and Amendment Deadlne?

i know the deadline is 1/31/2023 for 2022.

Client has some folks where they are sure of US income but not sure of state (California) tax status.

Can I file for then with only the Fed numbers and leaving the state blank? The California deadline for 1099 NEC seems to be 3/31 anyway.

Is this a good way to handle the problem? The reasons is the contractor receiving the 1099 may claim non residnecy in the US for 2022 any my client wants to help.

Can I file for then with only the Fed numbers and leaving the state blank?

Sounds good to me. The IRS doesn't really care what you put in the state fields, and you can file the California forms later.

the contractor receiving the 1099 may claim non residnecy in the US for 2022

Now this changes things. Is he a U.S. person or isn't he? If he is, file a Form 1099 (due today). If he's not a U.S. person, file a Form 1042-S (due March 15), and probably withhold like 30% tax or something (file Form 1042, also due March 15, and you're probably late on making tax deposits), there's a bunch of rules to watch out for.

my client wants to help.

Your client doesn't know what he's signing up for - look up the 1042 withholding rules.