how to get tax percentage based on zipcode

Question

i am building a custom ecommerce system. how do i get the most current tax rates based on the zipcode? i was thinking of just creating a table and listing all the state tax rates but the thing is the info changes yearly and it might be hard to track and update. would their be any apis that i can use? btw im using php

the one thing i need to be clear in us when a product is purchased, is the taxes applied only for shipping? or it needs to be applied for the item as well?

so would the total be calculated like this?

product: $100

shipping(ground) $4.75

tax(ca): 5%

total: 104.99

Answer 1

It is a little more complicated than just a zip code to a tax rate. Take a look at zip 2 tax. The tax rate is also effected by what you are selling. Some places do not place a sales tax on food. Some places tax "hot" food but not food that you take home to cook. So a grocery store will charge a tax rate for noodles that is different than a pre-cooked chicken from the Deli. Some places have a tax on junk food - any food that is more than X % sugar. It can vary by county. It can vary by location where some people are in a city and other are not in the city in the same county.

Answer 2

Try this service

http://dor.wa.gov/Content/FindTaxesAndRates/RetailSalesTax/DestinationBased/ClientInterface.aspx