Every tenant is responsible for any amount due to the landlord (e.g. rent, or money for damage to the property).

This means that, regardless of who ‘actually’ owes money to the landlord, the landlord is legally allowed to pursue any tenant for any money owed. An example: if one tenant doesn’t pay the rent, then if joint and several liability applies, all the other roommates are liable to the landlord for payment of that person’s share (or they can all be evicted for non-payment of rent). In this situation, it’s up to the other tenants, not the landlord, to collect from the non-paying tenant (say by suing them for damages).

The existence of joint and several liability means that, the more people you sign into a joint tenancy with, the more likely you are to be liable for more rent than you ‘should’ owe. Any guarantor for someone tied into a joint and several liability contract will also be potentially liable for the full sum owed for any rent payments or damages.