Tax in Canada in Provinces with VPT

[jridel]

In some provinces, such as Saskatchewan, three rates are applied to the product (VPT 20%, GST 5%, and PST 6%). In the case of GST, it must be applied to the value of the product plus the VPT value.

Using the system provider, it always applies the standard Canadian rate (HST), and even when configuring the other rates in the province, it does not apply two rates to the same product.

Furthermore, there is no setting to indicate that the calculation basis for one tax (GST) is the value of the product plus the result of another tax (VPT).

By creating a custom tax provider, I can apply all three rates, but I have no option to change the calculation, and the GST remains incorrect. Example of how the calculation should be:

A) Product Total.......: 100.00
B) VPT 20% (A*20%).....: 20.00
C) GST 5% (A + B * 5%): 6.00
D) PST 6% (A*6%).......: 6.00

Example of how the calculation is being done:

A) Product Total..: 100.00
B) VPT 20% (A*20%): 20.00
C) GST 5% (A * 5%): 5.00
D) PST 6% (A*6%)..: 6.00

Is there any way to change the GST calculation basis to A+B?

[gfernandez-me]

+1

I’m running into the exact same limitation and also need to implement tax-on-tax (e.g., GST over VPT) in Canada.

Current TaxProvider lets us define tax lines, but we can’t change:

• the taxable base for a line (e.g., make GST apply on subtotal + VPT), or
• the calculation order/dependency between taxes.

This blocks us from doing a compliant calc like:

A) Product Total.......: 100.00
B) Tax1 5% (A*5%).....: 5.00
C) Tax2 5% (A + B * 5%):  5.25
D) Tax3 10% (A*10%).......:  10.00

Right now GST is computed on A only.

Can we get either a hook to set the base and dependsOn per tax line, or a pluggable calculation strategy so a provider can return final amounts in order? I'm happy to help with an RFC or PR if you can point to the preferred approach / file to extend.