5 costly tracking faults impacting almost every Shopify store

16 September 2026

Charlie Semmence

In our UK State of Tracking 2026 report, almost every one of the 500 UK Shopify brands we audited had at least one broken tracking issue across Meta, Google Ads or GA4. Here's exactly what's breaking, and how often.

1. Missing parameters - 442 stores (88%)

What's the issue?

Missing parameters was the most widespread issue we found, impacting 88% of the brands audited. This occurs when events fire, but with incomplete data attached, for example a missing conversion value, currency code, product ID, or hashed customer identifier that the platform needs to reliably match and value the event.

What this means

Meta and Google can still record a Purchase, but they can't tell how big it was or connect it to a visitor with confidence.

Value-based bidding strategies - Meta's Highest Value, Google's Target ROAS - are built entirely on the conversion values they receive, so missing values mean the algorithm is optimising on guesswork rather than your actual best customers.

Budget allocation across campaigns and audiences follows the same broken signal, which means spend can drift towards the wrong products or segments without anyone noticing.

2. Cookie consent issues - 370 stores (74%)

What's the issue?

The next most common issue relates to cookie consent, impacting almost ¾ brands audited. This occurs when non-essential tracking fires before a user gives consent, or after they have declined consent.

What this means

Tracking someone without a valid legal basis breaches GDPR and UK data protection requirements, which can result in fines.

It also makes the data unreliable, since platforms model estimated conversions for visitors who declined based on patterns from real ones. If tracking's broken, those estimates are built on bad data too.

3. Google Consent Mode errors - 345 stores (69%)

What's the issue?

Less common but still impacting most brands are issues related to Consent Mode - Google's mechanism for modelling conversions it can't directly observe once a visitor declines cookies. For example, Consent Mode is incorrectly implemented or non-compliant.

What this means

Where it's set up wrong, Google Ads and GA4 either miss the conversion outright or fall back to a broad statistical estimate rather than an observed one.

Smart Bidding relies on a steady stream of real conversion signals to optimise. When you feed it modelled guesses instead, bid strategies drift, typically pushing budget towards keywords or audiences that look cheap on paper - rather than ones that are actually converting.

4. Missing events - 258 stores (52%)

What's the issue?

This is the most worrying issue we found. For over half of the stores we checked, at least one of the five core events in the customer journey - Page View, Product View, Add to Cart, Begin Checkout, or Purchase - wasn't firing at all.

What this means

A missing event isn't a small gap. Losing Add to Cart or Product View removes the signal dynamic retargeting and prospecting campaigns rely on to build audiences and know who to show ads to next. It also breaks any bidding strategy set to optimise towards mid-funnel actions, rather than just Purchase.

Budget ends up allocated on a partial view of the funnel, favouring whichever stage is still visible over the ones that would actually explain where customers are dropping off.

5. Duplicate tracking - 196 stores (39%)

What's the issue?

The least common issue on this list, but still not a minor one: the same event firing more than once for a single customer action, usually from two tracking implementations running in parallel.

What this means

Duplicates inflate conversion counts and skew the numbers used to judge campaign performance. Because those inflated numbers feed straight back into automated bidding, platforms can end up chasing a CPA or ROAS target that's wrong.

And since duplication rarely hits every platform equally, it can make one channel look artificially more efficient than another, pulling budget towards the wrong side of the split.

Why this matters

These faults rarely happen in isolation. 92% of the 500 sites we checked had two or more of these issues at the same time - and that’s where the bigger problems start.

A store with Missing Parameters and Consent Mode issues isn't just losing a bit of data accuracy - it's losing visibility into a meaningful share of its actual customers.

For paid media, that means bidding, budgeting and targeting decisions built on a picture of your customers that's fundamentally wrong.

The question for ecommerce brands isn't whether your tracking has one of these primary issues. It's how many - and what they're actually costing you while they sit unnoticed.