I've come up with a solution that works for me.
Try it out and see if it does the trick.
I have a similar situation in the state of Georgia,
I have a shop that needs to charge a different tax rate depending on where the item is shipping to.
The solution below sets up tax depending on the destination county. You should be able to follow these instructions if your taxes is by Zipcode. Just follow the directions below but instead of using county just use zipcodes.
Here is how I got it to work for me. I hope it works for you.
Its a tad bit tedious but it gets it done. No programming required.
Before I set up my Zone Groups, I have to go a step further back. I have to go to Countries
1. I went to countries Start > Definitions > Countries
You will notice all the countries listed.
2. I select United States on the left side. This shows me a list of states on the right side.
3. Where the states are, create a new state by clicking Add.
I created a series of new states, basically naming each by STATE - COUNTY.
In my case, I created the following:
Georgia - Cobb Co.
Georgia - Fulton Co.
Georgia - Mosqugee Co.
Georgia - Paulding Co. etc., etc.
OK almost there!
4. Next I went to Zone Groups Start > Definitions > Zone Groups
on the left side, I created new zone group and named it "Georgia - Cobb"
on the right, I crated a zone for it which was Country: United States, Zone: Georgia - Cobb
***Do this for each county - I told you it would be a tad bit tedious, but once youre done, youre done!
And Now for the home stretch!
5. I went to Tax Classes Start > Definitions > Tax classes
In my case, I only have one Tax Class called "Taxable Goods"
for that class, on the right side I created the tax rates by clicking on Add
Then I build the tax rate for each county!
When you click the ZONE GROUP drop down, you will see a beautiful list of your Counties,
Just assign the tax rate, and ensure to enter a description, i.e. "Cobb Co. Sales Tax"
Enter a priority # if you'd like
Just make sure that your products are marked as Taxable Goods!
Now when the buyer goes to check out, they will need to enter their shipping and billing address. When they go to enter their state, they will see a list of STATE - COUNTY. Since there will not be an option for GEORGIA itself, the person would intuitively know that (s)he needs to select their State/County. When the do this, the Totals in the checkout confirmation page will reflect the appropriate tax rate for the buyer's county.
Give it a try and let me know how it works for you!