This section applies for the purposes of sections 17 to 20.
The Secretary of State may inquire into and decide a person's age.
A claim for asylum shall be treated as determined at the end of such period as may be prescribed beginning with—
the date on which the Secretary of State notifies the claimant of his decision on the claim or (as the case may be) of the declaration of inadmissibility under section 80A or 80B, or
if the claimant appeals against the Secretary of State's decision, the date on which the appeal is disposed of.
A notice under subsection (3)(a)—
must be in writing, and
if sent by first class post to the claimant's last known address or to the claimant's representative, shall be treated as being received by the claimant on the second day after the day of posting.
An appeal is disposed of when it is no longer pending for the purpose of—
Part 5 of this Act, or
the Special Immigration Appeals Commission Act 1997 (c. 68).