No. UCD will be designed to avoid – at the infrastructure level – any unique identifiers for individuals, making it more difficult for counterparties to exchange personal data between their back offices without involvement of the individual. Instead, they will need to ask the individual, via their PDS account, to disclose the data.
Note, however, that some parties will require an individual to disclose personal data capable of being used as a unique personal identifier (such as the triad of name, date-of-birth and postcode; or an email address; or a phone number) at the point they sign-up. In this case, the individual can either comply or choose to walk away.