United Kingdom - Passport & Nationality - British Citizenship by Birth (After 1982)
A claim for British Citizenship by birth applies where:
1) you were born in the UK after 1982; AND
2) a parent was considered "Settled" at the time of your birth.
This "Settled" status includes both British and Irish citizens, a person who held the Right of Abode or Permanent Residency in the UK. If this was the case, you were born British.
However, if a parent was not considered "Settled", then it is still possible to be registered as a British citizen if:
a) you lived in the UK for the first 10 years of your life; OR
b) you are under 18, and a parent becomes "Settled".