Google charges digital service taxes for advertising in certain countries (e.g., a 5% surcharge for ads in Austria). These taxes are only shown on invoices, not in account statistics. Custom columns solve this problem.

1. Name your campaigns to indicate the countries they cover.

2. Specify the name or country code for each country below.

Find custom formulas based on your inputs below. Copy them into your account and use them at the campaign level.

For each of the columns above, create a new custom column. It's important that you start with the first column because all the others reference this one.

For each column, copy and paste the parts from above:

1. The column name and description (optional)

2. The data format: Make sure to set this one correctly as you cannot change it after.

3. The formula: Switch to text input or you won't be able to paste it. Don't worry if the format looks horrible. If you can save it, everything is ok.

At the end, don't forget to check if everything works correctly.