No. Your sign-in method is set when you create your account and can't be changed afterward — that applies to Google, Apple, and email/password.
If you want to use a different sign-in method, you'd need to delete your current account and create a new one. Account history and autopayments don't carry over.
If you're locked out of the method you originally used, contact support and we'll help you get back in.
Note for Apple users: If you signed up with "Sign in with Apple," your account email may show as either your iCloud address or as a private relay address (something like xxxxx@privaterelay.appleid.com). Both are valid — Apple's private relay forwards email to your real iCloud inbox without exposing it.
⚠️ Important — read before deleting: If you pay your bills through a portal, lender, or mortgage servicer using Split Pay account and routing numbers, do not delete your account. Your Split Pay account and routing numbers are tied to your identity and stay with you — individuals only get one Split Pay account. Deleting yours would orphan the payments saved in your portal or with your lender. Contact support instead and we'll help you sort out the sign-in method.