Some products have different tax codes, for example fresh fruit and vegetables in some countries do not attract tax. This can be easily managed within Vend.
When you set up your taxes, you will have chosen a default tax rate for each outlet in your store. You can override this for individual products.
Product variants must all have the same tax rate. If you change the individual tax rate on the product's main page (the parent product), all of the other variants will also be updated.

If you've got lots of products you need to update, you can update these using a CSV import.
Before starting, make sure you read our guide to editing products via CSV.

If you're using Xero, you may like to ensure the account you send sales of this product to has the same tax rate as the custom rate you've just set in Vend.
Here is an article explaining how to override default Xero account mappings.