# How to check whether your conversion tracking can be trusted

> Five checks you can do yourself before you spend another euro on ads.

Source: https://neoperforma.com/guides/check-conversion-tracking/  
Author: Afshin Hosseingholinezhad  
Published: 2026-10-07

## In short

- A conversion should be counted once, with a value and a source.
- Your analytics numbers should be close to your real sales.
- If a visitor declines cookies, no analytics or advertising cookies should be set.

## 1. One sale, one conversion

Place a test order, or send a test enquiry. It should appear once in GA4 and once in Google Ads. If it appears twice, a tag is probably installed both in the site code and in Tag Manager, or it fires again when the thank-you page is reloaded.

## 2. The numbers match your back office

Compare last month's purchases in GA4 with the orders in your shop or CRM. Some gap is normal, because visitors who decline cookies are not counted. A large or sudden gap means something is broken.

## 3. Consent is respected

Open your site in a private window and decline cookies. Then look at the cookies your browser has stored. Analytics cookies such as `_ga` should not be there. If they are, your banner asks the question but does not act on the answer.

## 4. Every conversion has a value

A purchase should send its revenue and currency. An enquiry should carry a value you have agreed for a lead. Without values, ad platforms optimise for the number of conversions and not for what they are worth.

## 5. The source survives the checkout

If your payment provider shows up as a traffic source in GA4, sales are being credited to it and not to the campaign that brought the visitor. Add the payment provider's domain to the list of unwanted referrals in GA4.

## If a check fails

Each of these has a known fix. If you would like a second pair of eyes, we do this review for free: see the [tracking audit](https://neoperforma.com/contact/).

## FAQ

### How often should I run these checks?

After any change to your checkout, forms or cookie banner, and whenever your numbers move in a way you cannot explain.

### Do I need a developer for this?

Not for the checks. Some of the fixes need access to Tag Manager or to the site code.