Under the rules in the United Kingdom, anyone can request a copy of a certificate. A birth certificate copy is designated as a public record, and as a result, anyone can request a copy.
There is a caveat that if the birth occurred in the last 50 years, the full details of the birth has to be provided when making a request as a way to protect against identity fraud.
For these births, you will have to provide the full date, as well as the parent’s name, including the mother’s maiden name. Anything older than that should not require as much information, which is perfect if you do not have it.