A statutory adoption leave request form is not a piece of legislation, it is the documentary trigger that puts an employer on formal notice. UK employees acquire the right to adoption leave under the Employment Rights Act 1996 and the Paternity and Adoption Leave Regulations 2002, but that right only crystallises once the employee gives proper notice and proof. The form is how the notice and the proof arrive together.
It is worth being precise about what this document is and is not. It is not a maternity form, even though the leave structure mirrors maternity leave closely, and it is not the same as a shared parental leave notice, which is a later election an adopter can make to split the balance of leave with a partner. A single adopter, or one member of an adopting couple, uses the adoption leave form; the other partner typically uses a statutory paternity leave request instead, since only one person in a couple can take adoption leave. The form records who is the main adopter, the date the employee was notified of the match, the expected placement date, and the date the employee wants leave to begin. Getting the main-adopter designation right at this stage matters, because it determines which statutory regime each partner falls under and which evidence each must supply. Employers reviewing the completed form should treat it as the foundation document for the whole absence, from the first payroll instruction to the eventual return-to-work date.