Under the Economic Crime (Transparency and Enforcement) Act 2022 all overseas companies must register at Companies House. They will be added to the Register of Overseas Entities and given a registration number. If you are acting for an overseas company that owns or wants to own property in England and Wales, then you need this number early in the proceedings. You must not exchange contracts without it, unless you have a contract conditional on registration. Failing to register is a criminal office and an indicator of money laundering. It also means the transaction on which you are advising cannot be registered.
Keystone cannot arrange a registration as it requires us to provide confirmations of identity of the client that are beyond our ability to state with complete certainty (an exception would be if we have set the company up recently). Companies House keeps a register of providers who can get overseas companies registered which you can view here.
Note that without a registration number the transaction cannot be registered at HMLR. For further information see Register of Overseas Entities: How it affects land transactions.