This is 3 months, beginning with any day on which, apart from
satisfying the conditions for making the claim, the person making
the claim is entitled to the benefit or allowance.
Different rules apply for refugees, see CBTM10140
Anyone making a claim must furnish any certificates, documents, information
and evidence in connection with that claim, or any question arising out of
it, as may be required by Her Majesty's Revenue & Customs.
If a person is required to furnish a certificate of the birth or adoption of a child or a qualifying young person, the certificate must be an original certificate or a copy authenticated in such a manner as to render it admissible in court proceedings.
They must do so within one month of being so required, or within such longer period as Her Majesty's Revenue & Customs may consider reasonable.