> ## Documentation Index
> Fetch the complete documentation index at: https://docs.upstackdata.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Event Coverage: Percentage of Events with Valid Match Keys

> Track what percentage of your events include valid customer identifiers for Meta matching. Improve coverage to boost EMQ scores and attribution accuracy.

<Tip>
  Event Coverage measures the percentage of your events that include at least one valid customer identifier (email, phone, etc.) that Meta can use for matching.
</Tip>

## Formula

<Info>
  **Event Coverage** = **Events with Valid Match Keys** ÷ **Total Events** × 100
</Info>

### Formula Components

| Metric                           | Definition                                                        |
| -------------------------------- | ----------------------------------------------------------------- |
| **Events with Valid Match Keys** | Count of events containing at least one valid customer identifier |
| **Total Events**                 | Total events sent to Meta during the period                       |

| Metadata        |                                   |
| --------------- | --------------------------------- |
| **Type**        | Percentage                        |
| **Data Source** | [Meta Ads](/sources/facebook-ads) |
| **Aggregation** | Average                           |

***

## Example

**Your store sends 10,000 events to Meta in a week.** Of those, 8,500 include at least one valid match key (email, phone, or external ID).

| Metric                 | Value     |
| ---------------------- | --------- |
| Events with Match Keys | 8,500     |
| Total Events           | 10,000    |
| **Event Coverage**     | **85.0%** |

***

## How It Works

Meta evaluates each event you send via the Conversions API to determine if it contains usable customer identifiers. Events with valid identifiers (properly hashed emails, phone numbers, or external IDs) count toward coverage. Higher coverage means more events can be matched to Facebook users for attribution.

***

## When to Use

| Scenario                          | Action                                                                |
| --------------------------------- | --------------------------------------------------------------------- |
| Event coverage below 80%          | Add more customer identifiers to your event payloads                  |
| EMQ score isn't improving         | Check if coverage is the limiting factor before addressing match keys |
| Setting up new event types        | Monitor coverage to ensure identifiers are being captured             |
| Comparing pixel vs. server events | Identify which channel captures more customer data                    |

***

## Related Metrics

| Metric                                                                       | Relationship                                             |
| ---------------------------------------------------------------------------- | -------------------------------------------------------- |
| [EMQ Score](/reference/metrics/data-quality/emq/emq-score)                   | Overall quality score that event coverage contributes to |
| [Match Key Coverage](/reference/metrics/data-quality/emq/match-key-coverage) | Breakdown of coverage by specific identifier type        |

[See all EMQ metrics →](/reference/metrics/data-quality/emq)