Charge one tax code for a specific State and pull the correct tax item based on the customer shipping address for other states.

If you need to charge one tax code for a specific State and pull the correct tax item based on the customer shipping address then you need to consider doing the following:

Assume that you have nexuses in New York, California and Texas. You need to charge taxes to customers in California and Texas based on the shipping address of the customer and only use one tax item for New York customers.

To facilitate the tax lookup, the following preferences should be set under Setup > Accounting > Set Up Taxes:
  --Enable Tax Lookup on Sales Transactions = checked
  --Charge Out of District Sales Taxes = checked
  --Default Tax Code = select the applicable tax item for the store/company location

--State-------------Home Tax Code
--NY-----------------blank
--CA-----------------blank
--TX-----------------blank

Make sure to inactivate all tax codes and tax groups associated to nexus New York except for the tax code/tax group you intend to use under Setup > Accounting > Tax Code and Setup > Accounting > Tax Group.  Setting Charge Out of District Sales Taxes preference to true will pull the tax item based on the shipping address of the customer specified on the transaction.

If a sales transaction is entered for a customer in NY, NetSuite will automatically pull up the remaining active tax item for the said State.  For sales outside New York (California and Texas), NetSuite will pull up the corresponding tax item based on the shipping zip code.