For my SaaS company, I charge my customers via Stripe, PayPal and some other payment platforms. Sales tax is different in every country, and in the US it is even different per state.

How does your SaaS company handle sales tax? Do you use the country and secondary (zip code or state) of the saved credit card or have some sort additional form? I can imagine a scenario where company A is based in California but uses a credit card from NY. In that case they should pay CA sales tax but if I were to use their credit card information, it would be NY sales tax.

This feels like a problem that has been solved by any international (or just US) SaaS company. Any tips would be greatly appreciated!