Attribution in Google Ads: What You Need to Know in 2025

If you manage campaigns in Google Ads, attribution is not just a technical detail. It is central to understanding what drives performance, how conversions happen, and where your budget is working hardest. When attribution is misunderstood or misconfigured, it can distort reporting, misguide bidding strategies, and lead to poor optimisation decisions.

This article covers everything you need to know about attribution in Google Ads in 2025, including the models available, recent changes, where to find attribution reports in the new interface, and how to use them effectively.

What is Attribution in Google Ads?

Attribution determines how Google Ads assigns credit for a conversion across the different interactions a user has before converting. These interactions may include clicks on Search ads, impressions on YouTube, or engagement with Display campaigns.

For example, a user might first click a Shopping ad, later view your video ad on YouTube, and finally convert after clicking a branded Search ad. Attribution is the system that decides which of those touchpoints deserves credit for the conversion.

Attribution Models Available in 2025

As of 2025, Google Ads supports only three attribution models:

1. Data-Driven Attribution (DDA)
   This is the default model for all new conversion actions. DDA uses Google’s machine learning to assign credit based on the actual impact each interaction has on the conversion path. It analyses real conversion paths and dynamically updates how credit is distributed as data patterns change.
2. Last-Click Attribution
   This model assigns 100 percent of the credit to the final interaction before the conversion. It is still available as an option but is no longer the default and is generally discouraged for campaigns with longer or more complex customer journeys.
3. External Attribution
   This model allows you to import conversion data from third-party tools that use their own attribution logic. It is useful for advertisers running multi-channel campaigns and needing platform-agnostic measurement.

Legacy Attribution Models Removed

In 2023, Google permanently removed four rule-based attribution models:

• First-Click
• Linear
• Time Decay
• Position-Based

These models are no longer selectable and have been fully removed from Google Ads’ Attribution reports. Their retirement reflects the shift toward more adaptive and data-informed approaches to measurement.

Data-Driven Attribution is Now Standard

Data-Driven Attribution is now the standard and recommended model in Google Ads. It is automatically applied to all new conversion actions. Unlike in the past, there is no longer a minimum data threshold required to use DDA. Even low-volume accounts will default to this model.

Key advantages of DDA include:

• Reflects the actual influence of each touchpoint
• Continuously updates based on new data
• Integrates directly with Smart Bidding strategies
• Accounts for cross-device and cross-channel user behaviour

If your account has sufficient volume, DDA will become highly tailored to your business. For smaller accounts, DDA still functions, drawing from broader aggregated models.

When to Use Last-Click Attribution

Last-Click Attribution remains available, though it is now less common. It may be appropriate in cases where:

• Your conversion paths are extremely short or direct
• Your stakeholders require simple reporting
• You are running legacy campaigns or need consistency with historic data

For most advertisers, Last-Click Attribution provides an incomplete picture and may undervalue top-of-funnel efforts like YouTube or Display.

Offline Conversion Tracking and Required Parameters

If you import offline conversions into Google Ads — for example, from your CRM or point-of-sale system — Google now requires the use of a parameter called conversion_environment.

As of 30 June 2025, this parameter is mandatory for all offline conversion imports. It indicates whether the conversion occurred on the web, in-app, or another environment. Including this parameter ensures that conversions are attributed accurately and that Smart Bidding has the right context to optimise effectively.

Failing to include this parameter may result in delayed or rejected conversion imports and reduced bidding performance.

Third-Party Attribution Tools

Google Ads attribution is limited to activity within the Google ecosystem. If your advertising strategy includes platforms like Meta, TikTok, Pinterest, or email, then you may benefit from an independent attribution solution.

Well-known third-party tools include:

• Triple Whale
• Northbeam
• Rockerbox
• Wicked Reports

These platforms provide cross-channel visibility and help you avoid over-attribution to one platform. They are most suitable for advertisers spending over £50,000 per month or running complex, multi-platform campaigns.

Where to Find Attribution Reports in Google Ads (2025)

Google Ads has redesigned the way attribution is accessed in the interface. It is now fully integrated into the goals and measurement framework.

To find attribution reports:

1. Open Google Ads
2. In the left-hand navigation panel, click Goals
3. Under Goals, select Measurement
4. Click Attribution

This section includes:

• Conversion paths – View the sequence of user interactions before a conversion
• Top assisting campaigns – Identify campaigns that contribute earlier in the journey
• Device breakdowns – Compare performance across mobile, desktop, and tablet
• Model comparison – Now limited to Data-Driven Attribution and Last-Click Attribution

If your goal does not use a conversion action that meets minimum reporting criteria, some attribution data may be unavailable.

Adapting to Privacy and Measurement Changes

The advertising industry is undergoing major changes due to privacy regulations, cookie deprecation, and shifts in browser technology. Google’s Privacy Sandbox, enhanced conversions, and modeled conversion reporting are all part of this evolution.

Attribution models like DDA are designed to operate effectively even when data is limited or modeled. However, advertisers must adapt by:

• Implementing enhanced conversions
• Using first-party data wherever possible
• Understanding that not all conversions will be directly observed in future reporting environments

Attribution accuracy will increasingly depend on using well-configured tagging, reliable data pipelines, and conversion modeling.

Key Takeaways

• Data-Driven Attribution is the default and recommended model for all advertisers in 2025
• Rule-based models like First-Click and Time Decay have been fully deprecated
• Last-Click Attribution remains available but should be used cautiously
• Attribution reporting is now accessed via Goals > Measurement > Attribution
• Offline conversions must include the conversion_environment parameter by June 2025
• Consider third-party tools if you run multi-platform campaigns
• Stay informed on privacy developments that affect data collection and modeling

Attribution is not just about reporting. It influences bidding, budgeting, optimisation, and strategy. Advertisers who understand and adapt to the new attribution landscape in Google Ads will have a clearer view of what works — and why — in a complex, multi-touch, cross-channel environment.