Tax calculation: the questions we get asked most

The advice here is unglamorous, which is probably why it gets skipped. The questions about tax calculation that come up most often on our calls.

Trust does most of the selling online, and trust is built from unglamorous details. The practical test is whether someone new to the project could tell, in a minute, that it had been handled.

Do we need to care about this?

Rules differ by destination and change without warning. Getting it slightly wrong is survivable. Ignoring it entirely is not. The failure mode is not doing it wrong, it is doing it once and assuming it stays done.

Can it wait until after launch?

Occasionally. More often the post-launch version costs several times the pre-launch one. Small and consistent beats large and occasional here.

How do we know it is working?

Automate it rather than maintaining tables by hand. The teams that handle this well are rarely the ones with the biggest budgets. It is worth deciding this deliberately rather than inheriting whatever the last person set up.

The short version

In e-commerce every friction point has a price attached, and the arithmetic is unusually easy to check. 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

None of this needs a rewrite. Most of it is a morning's work once someone decides to do it.