The UK immigration rules defines a dependant as a partner or child of the main applicant. Please note that only child dependants who are below the age of 18 can apply as dependants. However children over 18 may still apply as dependants provided they became 18 in the country as dependants.
In order for a dependant of a person with a UK ancestry visa to be granted entry clearance, they must be aged 18 and above on the date of they are due to arrive in the country. Note further, that child dependants must be under 18 years of age as at the time of entry. Child dependants who are over 18 may still be regarded as dependants under the immigration rules if they become 18 in the UK having had their entry clearance in the UK while under 18.
If you have a child whilst on the UK Ancestry visa, they may be able to make an application from inside the UK.
As a result of changes to the Immigration Rules which came into force since the 1st of October, 2013, switching into this UK immigration route is now allowable unless the applicant is on a visit to the UK or is on a temporary admission or release in the country.
Please note that dependants applying to switch must be over the age of 18 years as at the date of application. Child dependants applying to switch under this route must also be under the age of 18 as at the date of the application.
Individuals looking to extend their stay as a dependant of a person with a UK ancestry visa are able to extend their leave to remain in line with when the main applicant (the holder of the UK Ancestry Visa
Dependant of a person with a UK Ancestry Visa ILR
If you are currently in the UK as a dependant of a person with a UK Ancestry Visa, you can apply for ILR at the time the person your visa is dependent on is applying for his/her ILR.