What’s the minimum sample size for pay gap reporting, and what if we don’t meet it?

The Directive doesn’t set a hard minimum group size for pay reporting. But the general principle is clear: avoid reporting on groups so small that individual employees could be identified.

If a category of workers is too small, you’ll need to aggregate it with others or apply privacy protections.
 

There’s no single EU-wide rule for minimum group size. Instead, employers are expected to apply good judgement and align with broader data protection principles (such as GDPR).

Common guidance includes:

• Avoid publishing data for groups with fewer than 3–5 people.
• Aggregate small groups into broader job families or categories.
• Use anonymisation techniques (e.g. masking or rounding figures).

When employees request pay comparisons:

Even if formal reporting isn’t possible for small groups, employees may still ask for average pay levels. In those cases, employers should:

• Share aggregated averages, never individual salaries.
• Be transparent about why some data is withheld.
• Explain how pay relates to established salary bands.

Other considerations:

• Small samples can create volatility in results, making gaps look larger or smaller than they really are.
• Using rolling averages or multi-year comparisons can help smooth out spikes. Small sample sizes can also create volatility, where gaps appear artificially larger or smaller depending on current staffing. Smoothing techniques can help provide a truer picture
• Relying on employee “consent” to share pay data isn’t a safe solution - under EU law, consent in the employer–employee relationship isn’t usually considered valid.
   

To manage this, employers should:

• Define clear minimum thresholds for reporting.
• Build aggregation and anonymisation techniques into reporting systems.
• Prepare managers to explain why some information can’t be shared, without undermining employee trust.
   

Protecting privacy while delivering transparency is a delicate balance. Handling small groups carefully ensures your reporting is credible and compliant — without exposing individual pay data.

Done right, this balance reassures employees that pay transparency is about fairness, not exposure.