İlkan Digital.

Blog · Restricted tracking

Custom conversions stopped after Meta's health restriction: why, and what to do

By İlkan Geldigitti ·

When custom conversions stop working on a health site, there are usually two causes, and they look the same in Ads Manager: the numbers drop to zero. Either Meta flagged the custom conversion itself because its name or rule suggests a health condition, so it can't be used in new campaigns. Or your dataset is in core setup: Meta now strips everything in a URL after the domain and every custom parameter, so a custom conversion built on "URL contains /knee-treatment/thank-you" or on a custom parameter has nothing left to match.

The fix is different for each. A flagged custom conversion needs a neutral replacement (or a review request if Meta got it wrong). A custom conversion broken by core setup needs a different signal: a standard event fired on the confirmed action, which still reaches Meta under core setup. This guide shows how to tell which case you're in, and how to rebuild the signal without breaking Meta's terms.

Checked against Meta's Business Help Center on 25 October 2026. Sources are linked in each section and listed at the end.

How custom conversions work, and why health sites break them

Custom conversions "let you create rules for events": you take a standard event, a custom event or All URL Traffic and filter it with URL rules (the page URL contains a keyword) or parameter rules (for example value greater than 50). Meta's own example combines both (About custom conversions for web). Many sites also use URL rules to log conversions without any event code, such as "a page view whose URL contains /thank-you".

On a health site, both kinds of rules are fragile:

  • URL rules depend on the part of the URL after the domain, which is exactly what core setup removes.
  • Parameter rules on custom parameters depend on data that core setup drops.
  • Names and rules that describe a condition ("Knee surgery lead", URL contains "/arthritis/") are what Meta flags.

Cause 1: Meta flagged the custom conversion

Meta's rule: "Advertisers must ensure their custom conversions do not suggest information not allowed under our terms." Its examples are a specific health condition, such as arthritis, and a financial status, such as a credit score (Understand restrictions on certain custom conversions).

What a flag means for your campaigns:

  • You can't use a flagged custom conversion when creating new campaigns.
  • For a running campaign that uses one, Meta suggests creating a new campaign, or duplicating it and choosing a custom conversion that isn't flagged.
  • Once a campaign is published, "you cannot remove or select a different custom conversion", so duplicate before you publish.

To resolve it, create a new custom conversion without the information that triggered the flag, or pick another existing one that doesn't include it. If you believe the flag is a mistake, you can request a review in Ads Manager (campaigns table) or in Events Manager (custom conversions page).

A neutral replacement means no condition, treatment or body part in the name, the rule or the URL it matches. "Booking confirmed" on a standard event is fine; "Arthritis consult booked" on a URL containing "/arthritis/" is not.

Cause 2: Core setup removed what the rule needs

Core setup "restricts the transmission of custom parameters and anything in a URL following the domain". Meta's example: https://jaspersmarket.com/clothes/summer/dresses?item=10 becomes https://jaspersmarket.com/ (About core setup).

That breaks custom conversions in predictable ways:

  • A URL rule like "URL contains /thank-you" sees only the domain, so it never matches again.
  • A parameter rule on a custom parameter sees nothing, because the parameter is dropped. Rules on standard parameters such as value and currency keep working.
  • A custom conversion built on a custom event depends on that event being allowed. Under any data restriction, custom events are blocked until you review and confirm them in Events Manager; you should confirm only those that follow the terms.

Core setup can be on because Meta placed your data source in a restricted category, because someone on your account chose such a category, because of repeated prohibited-information notifications, or because it was switched on in Events Manager.

Some datasets carry more than core setup: Meta can also restrict specific mid- and lower-funnel standard events, or restrict all events in certain regions. The guide to Meta health and wellness restrictions explains the three levels.

How to tell which case you're in

In Events Manager, for the dataset behind the custom conversion:

  1. Custom conversions page: is the custom conversion marked as flagged? Then it's cause 1.
  2. Settings → Data restrictions → Core setup: is core setup on? Then URL and custom-parameter rules can't work any more (cause 2).
  3. Settings → Manage data source categories: is the data source in health and wellness, and who assigned it?
  4. Diagnostics: are parameters listed under Event parameters blocked?
  5. Custom events: are any waiting for review, or blocked?

Both causes can apply at once. A custom conversion called "Back pain lead" with a URL rule on a health site in core setup is usually both flagged and unmatched.

The 5-minute check for the "Some website data blocked" banner walks through the same screens step by step.

The fix: standard events on the confirmed action

The replacement that core setup leaves intact is a standard event fired on the action itself, not on the page it leads to:

  • Fire Lead when your form endpoint confirms the submission, or Schedule when a booking is confirmed.
  • Keep standard parameters only: value and currency where they make sense, nothing that names a condition or a treatment.
  • Send the same event from the Conversions API with the same event_id, so Meta counts it once.
  • If you still need a custom conversion on top, for example to separate two form types, base it on that standard event and a neutral standard parameter, never on the URL path.

Under core setup, standard events with standard parameters keep flowing. If your dataset also has restrictions on certain standard events, check in Events Manager which ones still apply, and optimise for the deepest one that is allowed.

What not to do

These come up as quick fixes. They go against Meta's terms and tend to make restrictions stricter:

  • Renaming events so that a blocked event arrives under a neutral custom name.
  • Moving the thank-you page to another domain, or masking the domain, so URL rules match again.
  • A new Pixel, dataset or ad account to escape the category.
  • Encoding the treatment in a parameter, an ID or a URL fragment that "doesn't look like" health data.

Meta also states that its restrictions "are not a substitute for your own compliance mechanisms": you stay responsible for what your integration sends.

FAQ

Will my old custom conversion start working again if I fix the rule? A flagged one can't be used for new campaigns; create a new, neutral one. One that only stopped matching because of core setup won't match again while core setup is on, because the URL path and custom parameters stay removed.

Can I edit a running campaign to use the new custom conversion? Not after it's published. Meta's suggestion is to duplicate the campaign, select the non-flagged custom conversion, then publish the duplicate.

Do custom audiences have the same problem? Yes, in a similar way. Custom audiences built on URL or custom-parameter rules may fill slowly or not be available under core setup, and audiences that suggest prohibited information are flagged.

Can I just turn core setup off? Only if your account turned it on. If Meta turned on data restrictions, you can't turn them off. If you think the category itself is wrong, you can request a review of it in Events Manager.

If you'd like your custom conversions, events and parameters audited before anything is changed, the restricted health tracking service starts with exactly that.

Sources

Free tracking check

Stuck on this in your own account?

Free, within 2 business days. We look at your site from the outside, no account access needed. Fixes are quoted separately.