Mae ymfudo mewnol yn edrych ar achosion o symud tŷ rhwng gwahanol ardaloedd daearyddol yn y DU. Rhoddir yr ystadegau hyn at ei gilydd gan ddefnyddio tair prif ffynhonnell; Cofrestr Cleifion y GIG, Cofrestr Ganolog y GIG a'r Asiantaeth Ystadegau Addysg Uwch.
There were an estimated 2.85 million residents moving between local authorities in England and Wales between July 2014 and June 2015. This is the same level shown the previous year.
There were 53,200 moves from England and Wales to Northern Ireland and Scotland, compared with 45,600 from Northern Ireland and Scotland to England and Wales. This means there was a net internal migration loss for England and Wales of 7,600 people.
For the total number of internal migration moves the sex ratio is fairly neutral; in the year to June 2015, 1.4 million (48%) of moves were males and 1.5 million (52%) were females.
Different migration-related data sources at local authority level including migration flows, non-UK-born and non-British populations, National Insurance number registrations, GP registrations, and births to non-UK-born mothers.
2011 Census internal migration statistics for the UK give estimates that classify people and households in areas within the UK and those having moved from each area to elsewhere within the UK in the year preceding the Census.