Registering Deed/Declaration of Trust?

Is it necessary/a legal requirement to register our Deed of Trust on the title, as a restriction? Is it needed to make it legally enforceable? I know HMLR don't act as a file repository and only register its existence (as a restriction), but I'm getting conflicting info from researching the question. Background:We recently bought the property as tennants in common and updated the title re ownership as part of the initial conveyancing, but the Deed has just been finalised, so too late to add at time of purchase, and the Conveyancer won't commit to an answer either way. Thx

Chris - whether you register a Deed of Trust is up to you. We are not a file repository as you put it but trusts can be protected on the land register as appropriate. https://www.gov.uk/government/publications/private-trusts-of-land

We don't use the term tenants in common on the register - https://www.gov.uk/joint-property-ownership