Google Analytics Audit Services: What We Check and Find

Olamide Sule, founder of Dolphin Analytics: a digital analytics expert based in London delivering solutions for agency and in-house clients.

Most teams don’t need a new analytics tool. They need to know whether the one they already run is telling the truth. A Google Analytics audit answers that, and this page covers what a proper audit checks, what you get back, what it costs, and the two free ways to find out whether you need one. The five-layer audit described here is the one we run for clients most weeks. If you’d rather book it than keep reading, our Google Analytics audit page covers the five layers and what it costs.

What is a Google Analytics audit service?

A Google Analytics audit service is a structured review of your GA4 and Google Tag Manager (GTM) setup that confirms whether the data is accurate. It works through data collection, key events, Consent Mode and reconciliation against a source you trust, then hands back a findings report. The goal is one plain answer: can you trust the numbers you report on, and if not, exactly where they break.

That’s different from a dashboard refresh or a new tool rollout. An audit doesn’t add features. It pressure-tests what’s already there, because a confident-looking report built on broken tracking is worse than no report at all. You act on it, and you act on the wrong thing.

What does a Google Analytics audit actually check?

A Google Analytics audit checks five layers, in the order that catches the most damaging faults first. Data collection comes first, then events, then consent, then reconciliation, then the reporting on top. Working through them in sequence stops you fixing a dashboard when the real problem is one bad tag underneath it.

• Data collection. One clean data stream per domain, the right Measurement ID firing on every page, no duplicate GA4 tags inflating sessions.
• Events and key events. The actions the business measures (purchases, leads, sign-ups) fire once, carry the right parameters, and are marked as key events so they reach your reports and Google Ads.
• Consent Mode. EU and UK visitors are handled correctly, so you aren’t silently dropping a chunk of traffic or, worse, collecting data you have no consent for.
• Reconciliation. GA4’s numbers get checked against a source of truth like Shopify or the CRM, because a gap between them is the fastest way to spot tracking that’s quietly failing.
• Reporting and integrations. The BigQuery export, Google Ads links and Looker Studio dashboards on top all read from the same clean base.

For the full pass-by-pass version, the GA4 audit checklist and the Google Tag Manager audit checklist walk through every check with the fault each one catches. This page is the offer; those two are the method.

What do you get back from the audit?

You get a written findings report, not a verbal “looks fine.” Each issue is named, ranked by how much it distorts your reporting, and paired with the fix and roughly what it takes to do it. A finance lead can read the summary; an analyst can act on the detail. That format is deliberate, because an audit that ends in a call nobody wrote down changes nothing.

The report answers three questions for every fault it finds. What is broken, in plain terms. What it costs you: which decisions you’ve been making on wrong data. And what fixing it involves, so you can decide whether to do it in-house or hand it over. Nothing in the report is a sales gate; the findings are yours whether or not you buy the fix.

What problems does a Google Analytics audit typically find?

Audits rarely find “nothing wrong.” They find tracking that looks healthy on the surface and leaks underneath: events firing twice, consent blocking more visitors than anyone realised, or a platform reporting revenue the till never saw. Here are three patterns we see often, drawn from real Dolphin engagements.

Marketing data with no attribution. For one private aviation client, an audit found that 88.6% of deal contacts had no web attribution at all: the enquiries were real, but the tracking couldn’t say where they came from. That gap is invisible until someone reconciles the CRM against analytics, which is exactly what an audit does.

Ad platforms overclaiming revenue. A subscription box brand’s ad dashboard overclaimed revenue by 6.9x against Shopify-confirmed sales. The channel was still profitable, but the reported figure was steering budget decisions that the real number wouldn’t support. An audit catches the gap by reconciling the ad platform against the source of truth.

Normal gaps mistaken for broken tracking, and broken tracking mistaken for normal. A Shopify versus GA4 purchase gap of roughly 10 to 15% is usually normal: consent-blocked sessions, ad blockers, refunds and dropped pixel events all explain it. An audit tells you which side of that line you’re on, so you don’t rebuild working tracking or trust a gap worth investigating.

Findings on Dolphin engagements go through a review step where every number is machine-checked against source data before it reaches you, so the report you read is the report the raw data supports.

How much does a Google Analytics audit cost?

An audit is paid work. Prices vary widely across the market, and most agencies, us included, quote per property once the scope is clear. A single-property review usually takes half a day to a day. Larger estates (many properties, multiple domains, custom BigQuery pipelines) take longer, because each data stream needs its own pass through the same five layers.

There are two free ways to find out whether you need one, and neither is the audit itself. Sonar is our free scanner: paste a URL and it reports the tags, pixels and consent setup running on that page. It works from the outside, the way a visitor’s browser sees the site, so it needs no access to your accounts and catches nothing that only shows up inside them. The tell us what’s broken, or book a call. Both are genuinely free and neither is a cut-down version of the paid audit, because an external scan and a conversation simply cannot see what an audit inside the property can.

Should you hire an agency or run the audit yourself?

Run it yourself if you know GA4 and GTM well and have the time. The checklists linked above cover every pass, and GA4’s own DebugView plus the Tag Assistant extension handle most of the work without touching code. For a smaller, single-property setup, a careful in-house pass often finds the obvious faults.

Hire a Google Analytics audit agency when the numbers already look wrong and you need the cause found fast, or when you want a second pair of eyes an agency brings from seeing the same faults across many accounts. The person who built the setup is often the last to spot its blind spot. Paying someone to look properly is worth it at the point where a wrong number is already steering budget.

Where to start

If your GA4 numbers look off, start with the cheap checks before you commit to anything. Run Sonar on the pages that matter to see what is firing from the outside, in one click and with no account access. Then use the tell us what’s broken, or book a call. If a full audit is the right next step, we scope it and quote it, and you decide from there. Our Google Analytics audit page sets out exactly what the paid audit covers and how it’s priced. See how Dolphin Analytics works if you want the full picture first.