Marc Alexander, GA4 and Google Tag Manager consultant in London

Your GA4 is probably telling you things that aren't true.

Marc finds out why your GA4 numbers don't match reality, and fixes them so they stay fixed.

Experience includes Halfords Knight Frank Hertility Health The Super Prime

Exploded diagram of an illustrative tracking review, read from the top down in five layers. The problem, GA4 doesn't match what really happened: a bar marked GA4 stands well short of a bar marked CRM, the missing part drawn as a dashed outline, with a barn owl perched on top, a robot head beside them, a broken gear with its snapped-off piece on the left and a broken chain link in front. The investigation, every checkpoint reviewed: an audit checklist under a magnifying glass, with a cookie beside it. The fix, put right at the source: a round pipeline rising out of the layer at one end and going back into it at the other, with a spanner tightening the bolt on the coupling at its joint, two more spanners beside it, and a small puddle under the joint where it has been leaking. The checks, tested before it goes live: a test results sheet with every row ticked, a pencil beside it, a light switch marked on and off, switched on, and a padlock. The outcome, numbers you can trust: the CRM and GA4 bars standing almost level, in the same place as above, with a laptop showing a rising bar chart with a line through it, a king and a queen from a chess set, and a large stack of pound notes in banded bundles.

Not sure where to start?

Describe the problem in your own words, or answer three questions, or run the tracking checker.

Marc Alexander

Who you'd be working with.

Marc is a senior GA4 and Google Tag Manager consultant in London, trading as Metric Owl. You work with him directly throughout.

Works with clients across the UK, Europe, the US, Canada, Australia and New Zealand. More about Marc

"It's been a real pleasure working with Marc. He's a talented and highly competent professional whose contributions across product development and analytics have been invaluable. I've appreciated his collaborative spirit and sharp insight. I would gladly recommend him to any team."

Megan McGregor, Partner, Digital Product Manager, Knight Frank

Sound familiar?

Start with a mini audit.

A focused review of your GA4 setup.

Mini audit from £175

3 to 5 working days

See the mini audit

What Marc does.

All prices

38-point GA4 audit

Every checkpoint reviewed, with a plan to fix it.

from £600

Expert GA4 setup

GA4 and GTM built around how the business makes money.

from £350

Server-side GTM

First-party data collection that respects consent.

from £2,000

GA4 to BigQuery

Raw GA4 data in BigQuery, with clean tables.

from £500

Custom GA4 dashboards

Data Studio reporting built around the decisions you make.

from £800

Tracking monitoring

Daily checks on key events and revenue.

from £500 a month

How healthy is your tracking?

See what a first-time visitor triggers before agreeing to anything.

Latest articles.

All articles

23 October 2026

VAT in GA4 revenue for UK stores

UK prices include VAT but GA4 expects revenue without tax. Why it overstates sales and return on ad spend, and how to send VAT in its own field.

Book a mini audit, or talk first.

Start with a GA4 mini audit, from £175, or choose "20-minute intro call" below.

Or email [email protected].

Marc replies personally, usually within one working day.