Combined taxes (GST + QST)

[FR6]

In Quebec (Canada) we have to apply two taxes to each sales:

• GST: Federal goods and services tax accross all of Canada (rate: 5%)
• QST: Quebec provincial sales tax (rate: 9.975%)

The particularity is that the QST is calculated after GST, which makes the effective combined rate slightly higher than just adding 5% + 9.975%.

How can we configure this in Cargo?

[duncanmcclean]

I'd create one tax zone for Canada for federal taxes, than another for Quebec's sales taxes. They'll stack on top of each other (hopefully in the right order 🤞).