Are you asking about CA use tax? Here is some more information from the Franchise Tax Board:
If you bought tax-free things online, in another state, or in a foreign country, you may owe use tax.
Use tax applies to out-of-state purchases made by:
- Phone
- Internet
- Mail
- In-person
And both of the following apply:
- The seller does not collect California sales or use tax.
- You use, give away, store, or consume the item in this state.