The registration certificate issued by HMRC is the schemes confirmation that it is a registered pension scheme. The scheme must keep this as they may need to produce this letter at a later date - for example to prove to another pension provider that the scheme is formally registered with HMRC in transfer proceedings.
If, as a pension provider, you are needing this because one of your members are wanting to transfer their benefits into the NHS Pension scheme you can email us to request this firstname.lastname@example.org.
Alternatively you can write to us:
PO Box 2269