Setting up tax classes allows you to use different tax rates for different countries.
1) First, we have to set up a Geo Zone, so go to System.

2) Then Localisation.

3) And click Geo Zones.
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4) Click Insert.

5) Enter a Geo Zone Name.

6) Type a Description.

7) Click Add Geo Zone.
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8) Select the Country from this dropdown.

9) Select the Zone.

10) Add another zone by clicking this button.

11) Again, select the Country and Zone.

12) Click Save.

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Now that we have our zone setup, we can apply it to a tax rate.
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13) Go to System.

14) Then Localisation.

15) And click Tax Classes.
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16) Click Insert.

17) Enter the Tax Class Title.

18) Type a Description.

19) Click Add Tax Rate.
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20) Select the Geo Zone we created.

21) Type a Description.

22) Set the Tax Rate here.

23) Enter the Priority.

24) Click Save.
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That's it! Now you know how to setup tax rates in OpenCart.
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