Yes, and if you aren't sure, you can ask them to fill out an accredited investor questionnaire.
(Disclaimer: This is not a legal advice and you should consult your own attorney before doing anything involving securities law). They technically do not have to be accredited, as there are ways to do it under very specific conditions using a Reg CF qualified portal partner. BUT, it’s not something that other investors will tolerate. It will cause far too much friction in the later raise if you have non-accredited investors in the SAFE round. That said, as long as you're not doing any sort of public solicitation, you can rely on self-certification of their accredited status https://www.sec.gov/smallbusiness/exemptofferings/rule506b