Tenants renting under an Assured Shorthold Tenancy agreement have a right to know who there landlord is and there serviceable address*.
Your landlord should give you their name and address when you sign the tenancy agreement. If you sign the agreement with a agent they should provide these details.
If your agent does not give you this information you can request it.
You should write to your agent and request the information.
Request for landlords details LETTER TEMPLATE
Note: * a serviceable address must be in the UK, but does not have to be the landlord home address.