Whatever the reason for the move, the increase in Britons abroad has led to a number of people asking whether or not children who are born abroad are British. This is an important question as if a child is not British, the child will not have an automatic right to return to the UK in the future. The question of whether or not someone born outside the UK is a British national is not always an easy one to answer. The Home Office website contains a useful tool: which can be used, but this is only a starting point and will often give the answer that someone "may" be British.
When I receive enquiries of this nature, my starting point is always to consider the British nationality of the parents. You might wonder why - surely if someone has a British passport, then they are British? However, this is only half the story. There are, in fact, two types of British nationals - those who are British by descent and those who are British otherwise than by descent.
The two 'types' of British nationals
Children born in the UK, with British parents, will automatically be "British otherwise than by descent". Someone who acquires British citizenship in this way can pass British citizenship on to his or her children regardless of where their children are born.
Children born outside the UK, with British parents, are usually considered "British by descent". If someone is British by descent, they cannot pass British citizenship onto their children who are born outside the UK. Instead their children will not be automatically British but may be able to register as British nationals if they meet certain requirements.
The situation is made more complicated by the fact that British nationality laws have undergone several changes over the years. The effect of this is that someone's date of birth can affect their claim to British citizenship, particularly where their parents were unmarried at the time of the child's birth. If a child was born before 1 July 2006 and their parents were unmarried, then the child could only become a British national if their mother was a British citizen. From 1 July 2006 onwards this is not an issue, and there is now a route whereby children born before 1 July 2006 with an unmarried British father can register as a British national.