Limited Data Use (LDU) is a data processing option Meta offers to advertisers. When enabled, Meta processes data coming from the relevant region only for limited, predefined purposes.
This option is designed specifically for compliance with privacy laws enacted at the US state level. LDU isn’t a requirement on its own — it’s enabled based on the advertiser’s own compliance assessment. But once enabled, measurement and targeting capabilities narrow accordingly.
Meta’s data processing options documentation states that when LDU is enabled, Meta processes data from the relevant states in the role of a service provider and for a limited purpose, and that this can affect campaign performance, remarketing, and custom audience sizes.
What Is Limited Data Use?
LDU is a setting that lets Meta process user data from certain regions within a narrower framework than its standard processing purposes. It’s enabled by the advertiser through the Pixel, Conversions API, or App Events.
It isn’t on by default
LDU isn’t enabled automatically. It’s expected to be turned on based on the advertiser’s own legal assessment, which is why it isn’t applied the same way across every account. For example, a business operating only in California and a business selling across the entire US might enable the same LDU setting for different reasons — or not enable it at all.
The service-provider role differs from standard processing
When LDU is enabled, Meta acts more like a service provider, processing data only for the limited purposes the advertiser requests rather than for its own general advertising systems.
Which Regions Does It Cover?
LDU is designed primarily for compliance with privacy laws enacted at the US state level. Its coverage can expand as new state laws take effect.
Legal variation by state
Rather than a single federal privacy law, the US operates under state-by-state regulations. This means compliance needs vary from state to state.
Coverage isn’t fixed
As new state laws are added, the list of regions LDU covers is updated accordingly. You need to check Meta’s own documentation for the current list — the information in this article is a snapshot in time.
What’s the Impact for Advertisers?
The purpose of enabling LDU is compliance, but its side effect shows up in measurement and targeting.
Campaign performance may appear to drop
Meta’s official documentation states that campaign performance reporting can be affected when LDU is enabled. This means the campaign hasn’t actually gotten worse — measurement has narrowed — and that distinction is the key thing to keep in mind. Making decisions without comparing the sales team’s own records against the panel can be particularly misleading here.
Custom audiences and remarketing can shrink
Customer-list-based custom audiences and site-visitor remarketing can end up working with smaller audience sizes for data covered by LDU. For example, if a meaningful portion of a 20,000-person email list comes from states covered by LDU, the resulting custom audience can come out noticeably smaller than that 20,000.
How Does LDU Relate to Other Privacy Layers?
LDU isn’t a standalone solution — it needs to be evaluated alongside platform restrictions like Safari ITP and iOS ATT.
Layers stack on top of each other
If a user is coming from both an ITP-restricted browser and a state covered by LDU, the measurement loss doesn’t come from a single restriction — it’s the sum of several layers.
Relying on a single signal increases risk
Server-side measurement (Conversions API), Meta Aggregated Event Measurement, and first-party data matching can reduce the impact of these layered restrictions, even if they can’t eliminate it entirely.
One of the laws LDU is built around is the CCPA
California is the first and best-known of the states covered by LDU. For the scope of this law and its definition of “sell/share,” see What Are the CCPA/CPRA?
Pre-Launch Check
To correctly read measurement narrowing caused by LDU:
- Which accounts/campaigns have LDU enabled, and which don’t?
- Does the performance drop in affected regions line up with the date LDU was turned on?
- Is the legal compliance requirement current, or is it based on an outdated assessment?
A Common Mistake
The most common mistake is applying LDU the same way across an entire account or all regions, and mistakenly attributing performance in unaffected regions to LDU as well. The impact only applies to the regions actually covered.
Summary
Limited Data Use is a data processing option Meta offers for compliance with US state privacy laws. When enabled, data from certain regions is processed for limited purposes, which can narrow campaign reporting, custom audiences, and remarketing. Its impact should be evaluated alongside other platform restrictions like Safari ITP and iOS ATT.