The simple answer

Learn when a Google Ads data exclusion can protect Smart Bidding from broken conversion data, how to set the date range, and what not to exclude.

A Google Ads data exclusion tells Smart Bidding to reduce the influence of conversion data from a period when tracking was broken or inaccurate. It does not delete conversions from reports, repair the tag, or erase a bad sales period.

Use a data exclusion for a confirmed conversion-data problem, such as a broken tag, duplicated conversions, a website outage, or failed offline uploads. Do not use it to hide ordinary poor performance or a promotion that converted differently than expected.

What data exclusions do

Smart Bidding uses conversion and conversion-value data to set bids. Bad data can teach the system the wrong lesson.

Examples include:

A data exclusion tells eligible bidding strategies not to rely normally on the affected click data.

It does not remove the conversions from the visible Google Ads reports. Reporting corrections and bidding protection are separate jobs.

When to use a data exclusion

Use one when:

  1. The problem is confirmed.
  2. Conversion counts or values are materially wrong.
  3. Smart Bidding used or may use the affected data.
  4. The start and end of the issue can be estimated.
  5. The affected campaigns and devices can be identified.

Google lists broken tracking, incorrectly placed tags, website outages, and failed data imports as common uses.

When not to use one

Do not use a data exclusion for:

If a brief future promotion should materially change the real conversion rate, consider a seasonality adjustment. If the tracked leads are real but low quality, fix the conversion definitions and send qualified outcomes back to Google.

Data exclusion versus seasonality adjustment

Situation Data exclusion Seasonality adjustment
Conversion tracking is wrong Yes No
Website outage prevents sales Often No
Three-day sale should lift real conversion rate No Possibly
Demand rises but tracking remains correct No Usually no
Offline conversions fail to upload Yes No

The distinction is simple: a data exclusion handles bad measurement; a seasonality adjustment handles a real, expected behavior change.

How to choose the date range

Google applies exclusion dates to clicks, not only to the moment the conversion would have been recorded. Account for conversion delay.

Suppose offline conversion uploads failed from October 15 through October 18, and customers normally take up to five days to convert after clicking. Google’s example extends the affected click window back to October 10.

The reason is that a click on October 10 may have produced a conversion during the broken upload period.

Do not automatically extend every issue by the same number of days. Use the account’s actual conversion delay and the conversion action that failed.

Google recommends covering at least 90% of clicks associated with the bad conversion data.

How to create a data exclusion

  1. Open Tools in Google Ads.
  2. Open Adjustments.
  3. Select the Exclusions tab.
  4. Select the plus button.
  5. Add a clear name and description.
  6. Enter the start and end date and time for affected clicks.
  7. Select the affected campaigns or the appropriate account scope.
  8. Select affected devices if the issue was device-specific.
  9. Review the account time zone.
  10. Save and create the exclusion.

Use the narrowest truthful scope. If only mobile tracking failed in two campaigns, do not exclude all devices across the account.

What to do before applying it

Confirm the tracking failure

Check the website, tag manager, CRM, call-tracking system, order platform, and Google Ads conversion diagnostics. Compare recorded outcomes with the system of record.

Fix the source problem

The exclusion does not repair conversion tracking. Restore the tag or upload process first when possible.

Record the exact timeline

Document:

Review bidding and budget risk

Google warns that bid and spend changes can still occur while the exclusion takes effect. Review bidding targets and daily budgets rather than assuming the account will immediately behave normally.

A simple error example

Suppose a campaign normally records 20 qualified conversions per day. A duplicated tag reports 60 for two days.

The bad count is:

60 ÷ 20 = 3 times the normal daily count

If the business actually received 20 qualified outcomes, optimizing toward the reported 60 could encourage Smart Bidding to pursue traffic that did not create real customers.

The correct response is to fix the duplicated tag, confirm the affected period, and consider a data exclusion. It is not to celebrate a temporary platform improvement.

What to do afterward

As of September 4, 2026, Google recommends waiting at least five days before backfilling excluded conversion data for reporting and advises against removing the exclusion. Check current documentation before acting because this guidance can change.

Frequently asked questions

Do data exclusions delete conversions from Google Ads reports?

No. Google says they affect the data Smart Bidding uses, not the conversions shown in reporting.

Can I use a data exclusion after a website outage?

Yes, when the outage prevented real conversions or caused conversion tracking to become inaccurate. Include the affected click window and conversion delay.

Should I backfill missing conversions?

Google generally warns that backfilling can disrupt bidding. Its current guidance says to wait at least five days after applying the exclusion when backfilling is required for reporting and not remove the exclusion.

How quickly does a data exclusion work?

Future exclusions typically take effect within about a day. Exclusions for past dates may take several days to stabilize performance, and longer outages may affect one or two conversion cycles.

Can data exclusions fix poor lead quality?

No. If the conversions were recorded accurately but the leads were weak, improve qualification, conversion goals, and offline outcome imports instead.

Sources


Want Better Results From Paid Media?

Darlington manages advertising and measurement for businesses that want clearer decisions and more profitable growth.

Talk With Darlington