Each application to the EU Settlement Scheme (EUSS) is considered on its individual merits.
The Impact Assessment for the EUSS (March 2019) is available at:
This discussed the assumptions, risks, uncertainties and exclusions surrounding its estimate of eligible citizens and made clear it should be considered as indicative and not as minimum and maximum estimates.
The estimate of EEA citizens and their family members who were potentially eligible for the EUSS, made for the Impact Assessment, was primarily based on ONS Annual Population Survey (APS) data, which estimates the resident population, adjusted to estimate how the resident population would change in the future. It therefore cannot be directly compared to the number applications made to the EUSS.