Facts and figures relating to the migration of people into and out of Somerset

Somerset's population has been rising steadily in recent years. While part of this growth is attributable to there being more births than deaths within Somerset, net migration from outside the county is the major factor. The Office for National Statistics (ONS) publishes regular estimates of both international migration flows, of which the main component is the International Passenger Survey (IPS), and internal migration (between one part of the UK and another).

At a local level, registration data sources are often used to estimate changes in international migrant populations, although none are comprehensive nor 100% accurate. These include National Insurance Number (NINo Allocation to overseas nationals (collected by the DWP) and  New Flag 4 GP registrations (from the Patient Register Data Service).

The ONS also produces estimates of internal migration for England and Wales. However, measuring migration is not straightforward as there is no compulsory system within the UK to record the movement of the population. Therefore, it is necessary to use proxy data to make estimates of migration, largely based on patients moving and informing their doctor as they change residential address.The latest figures on flows into and out of each local authority, based on 2015-16, were published in June 2017.

Details of the different migration measures and data sources are available on the ONS website.

We have analysed figures for internal and international migration separately below, and we will update them as more information becomes available.

Pages in this Section

• Internal Migration
• International Migration