Before you invest in tax calculation

The advice here is unglamorous, which is probably why it gets skipped. Before you spend anything on tax calculation, it is worth confirming a few things are already true.

In e-commerce every friction point has a price attached, and the arithmetic is unusually easy to check. The teams that stay on top of it are the ones who put it on a calendar rather than a wish list.

Prerequisites

• You can describe the outcome you want in one sentence
• Someone owns it after the work is done
• Rules differ by destination and change without warning
• You have a way to tell whether it worked

Warning signs

Getting it wrong is a compliance problem, not just an accounting one. The teams that handle this well are rarely the ones with the biggest budgets. Doing this properly once is usually cheaper than doing it approximately three times.

Automate it rather than maintaining tables by hand. Where this goes wrong is almost never a lack of knowledge. The teams that stay on top of it are the ones who put it on a calendar rather than a wish list.

The short version

Small percentage changes matter here because they apply to every order, every month. Three things worth confirming about tax calculation before you move on:

• Someone can say what the current setup is without going to look
• Getting it wrong is a compliance problem, not just an accounting one — and you know whether that is true here
• There is a way to tell whether the last change to this helped

The point is not perfection, it is knowing which of these you have consciously chosen to skip.