Microsoft Advertising · Status at source date: Documentation coverage

Microsoft documents a 90-day CAPI event-submission limit

1 Nov 2026Written by Paid Media Collective

IN BRIEF

Microsoft’s current Conversions API documentation accepts eventTime values from the preceding 90 days. It recommends sending events as close to real time as possible. Hana Kobzová’s PPC News Feed report highlighted the guidance on 1 November 2026.

Microsoft CAPI schema: eventTime within 90 days, separate from attribution. Actual documentation captured 1 November 2026. Microsoft Learn documentation View full-size image

What changed

The important distinction is between submission and attribution. An event can satisfy the API’s age requirement without qualifying for attribution: it must also fall within the conversion goal’s configured attribution window. A successful upload therefore does not establish that a conversion will be credited to an ad.

For measurement teams, check the event’s actual occurrence time, the UTC timestamp sent in the payload and the relevant conversion goal settings. Backfilled events should not be assigned a fresh occurrence time merely because they are uploaded later. Review upload validation and reporting separately when investigating missing conversions.

This article describes the current documented rule. PPC News Feed reports that the earlier submission limit was seven days, but that historical comparison and the exact change date have not been independently established. The displayed 1 November date is the coverage date, not a confirmed release date. Hana receives credit for the documentation report; Microsoft is the policy and API documentation source.

A useful diagnostic record separates four questions: when the event happened, when it was submitted, whether the API accepted it, and whether it was attributed. Combining those into one success flag can hide the actual reason a conversion is absent from a report. When reconciling delayed uploads, retain the original event identifier and compare like-for-like periods. The 90-day ceiling should be treated as an acceptance boundary, not a recommended processing delay or permission to disregard the account’s attribution settings.