I am looking to buy a house to multi-let, but the house I've identified comes with an elderly long-term tenant on a long term contract. Can I serve notice for the tenant to leave or does a long term tenancy come with regulations to stop me doing this?
This sounds like a pre-1988 Regulated Tenancy. If it is, that is a lifetime tenancy, with possibly the right to pass the same agreement down to the next of kin.
You have zero chance of serving notice and any court will back the tenant 100% if you do.
Tenants like this, or those around them, have a highly developed awareness of the value of their tenancy. One such tenant in a central London flat was reported to have refused £500,000 in cash to give up the tenancy.
You have zero chance of borrowing any money to purchase it either, as no lender will touch it with a bargepole due to the tenant and their rights of occupancy.
This type of property has long been the preserve of affluent cash buyers. These properties normally go for 50% BMV. If the buyer has the cash to play the long game, they can double their cash investment on the death of the tenant, or vacation of the property due to long term care needs; plus any capital growth between purchase and the tenant having to leave.
If you can't afford to buy outright and wait for an unspecified period - look for a property without a Regulated Tenant.