A child born outside the UK has no entitlement to British citizenship and has to normally secure ILR first. If you can prove sole responsibility, the child can be granted indefinite leave to enter (ILE) and join you in the UK as settled. Then you can look into the citizenship.
Note that sole parental responsibility means that one parent has abdicated or abandoned parental responsibility, and the remaining parent is exercising sole control in setting and providing the day-to-day direction for the child’s welfare.
There are specific factors that will be considered in assessing sole responsibility:
•Whether the parents are married/in a civil partnership
•If the marriage/civil partnership is dissolved – which parent was awarded legal custody
•If the sponsoring parent has migrated to the UK – how long have they been separated from the child and what relationship they have with the child
•If the sponsoring parent has migrated to the UK, the nature of the child’s care arrangements before and after they migrated
•Who bears the child’s maintenance costs and at what proportion
•Who makes the important decisions about the child’s upbringing, for example, where the child lives, which school they attend, etc
The immigration rules cover this in detail under Appendix Children:
https://www.gov.uk/government/publicati ... e_parental
You are not considering whether the child’s parent (or anyone else) has day-to-day responsibility for the child, but whether the parent has continuing sole control and direction of the child’s upbringing, including making all the important decisions in the child’s life. If not, then they do not have sole parental responsibility for the child. You must carefully consider each application on a case-by-case basis. The burden of proof is on the applicant to provide satisfactory evidence that a parent has sole parental responsibility.
For entry clearance cases, it may be necessary to use local intelligence relating to the applicant’s home country or location to advise on what evidence you should expect to see, or what is likely to be available that you could reasonably ask for, as well as how much weight to give to particular types of evidence. Country-specific information can be found in the country of origin information or via the relevant UK embassy or high commission staff.
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