On 12 January 2026 Meta removed the 7-day and 28-day view-through attribution windows from its Ads Insights API, the source most reporting tools pull from, so any client report or dashboard that counted conversions in those windows now shows fewer than it used to with no change in real results; check which attribution window each report uses, set them all to one supported window such as 7-day click and 1-day view, and tell the client before they notice.
The pattern is familiar to agencies that report through Looker Studio, a reporting connector or their own dashboard: the conversion numbers in the client report fall, Ads Manager shows something different, and the client asks which one is true and what went wrong. Often nothing went wrong in the campaigns. The way conversions are counted changed underneath the report.
What Meta changed
Meta announced in October 2025, and switched on 12 January 2026, changes to the Ads Insights API, the interface reporting tools use to read campaign results. Two view-through attribution windows were removed: 7-day view and 28-day view. A view-through conversion is one credited to an ad the person saw but didn't click. The windows that remain are 1-day click, 7-day click, 28-day click, 1-day view and 1-day engaged view.
Meta said the aim was to reduce differences between the API and Ads Manager. The change was to the API, so it hit reports built on it, not the numbers inside Ads Manager itself.
- A report set to 7-day click and 7-day view, or anything with 28-day view, lost the conversions that were only in those windows.
- A request for a removed window now returns nothing rather than an error, so a dashboard can show blanks or zeros without saying why.
- Some breakdowns now only go back 13 months (unique counts and hourly breakdowns) or 6 months (frequency breakdowns). Year-on-year comparisons of those break.
When a report and Ads Manager disagree, check the attribution window before you check the campaign.
How much it matters for lead campaigns
Less than for e-commerce. Leads submitted on a Meta Instant Form come from people who tapped the ad, so they count as click conversions, not view-through ones. The drop shows most in website conversions tracked by the pixel, such as purchases and landing-page form fills, where view-through credit used to be a large share.
What to do
- Check the attribution window in every report and dashboard you send clients. Set them all to the same supported window, such as 7-day click and 1-day view, so the numbers agree with each other and with Ads Manager.
- Mark the break in any chart that runs across January 2026, so a client doesn't read a counting change as a performance drop.
- Tell clients first. A short note before the report ("Meta changed how some conversions are counted; your results didn't change") avoids a worried call after it.
- Judge lead campaigns on what the client's team sees: calls answered, site visits, sales. Those don't depend on an attribution window. See your sales calls are Meta's best targeting data.