Finding California sales taxes to be a big heachache, any ideas on how to do this with out of the box Netsuite? We don't have Suitetax

Totally agree! Plus New York. Looking for some ideas too

Wish i could help with NY, we don't have nexus there yet.

just use Avalara. The cost is less than a Tax Accountant or auditor

The primary issue with native NetSuite tax functionality is that it's zip code based. I'm not sure about CA, but in WA, zip code doesn't cut it. The exact geo-coordinates are needed to pinpoint the correct tax jurisdiction. Because of this, there's really no choice but to use SuiteTax and a third party data provider.