Setting Up Conversion Tracking Your Finance Team Can Trust

Conversion tracking is usually configured to serve the advertising platform. That is a reasonable starting point, but it leaves the numbers disconnected from the ones the business uses to judge whether the activity was worth funding.
Start from the definition of a conversion
Write down, in one sentence, what counts as a conversion and what does not. Cancelled orders, refunded purchases, test transactions and internal traffic should all be excluded before launch. Most discrepancies between platform reporting and internal reporting trace back to a definition that was never written down.
Send value, not just counts
A conversion action that records only a count cannot distinguish a large order from a small one, which limits both automated bidding and internal reporting. Send the transaction value alongside the event, excluding tax and shipping if that is how the business reports revenue.
Align the reporting window
Platform reports attribute a conversion to the day of the click, while finance records it on the day it clears. Both are correct and they will never match exactly. Document the difference in advance so that it is treated as a known characteristic rather than rediscovered every month.
Reconcile on a fixed date
Pick a monthly reconciliation date, at least a few days after the reporting period closes, and allow late-arriving conversions to settle before comparing. Comparing on the first day of the following month guarantees a mismatch that will be explained away rather than investigated.
Test the tracking after every site release
Add a tracking check to the release checklist. A single template change can silently break a conversion action, and the loss is invisible until someone notices the numbers look wrong.