no key

[monty1964]

if the tenant leaves and doesn't leave a key what do i do? can i change the lock to get in? where do i stand, have a feeling they wont leave key as this has been an unpleasant scenario with bad feeling please advise on legalities

[Ericthelobster]

if the tenant leaves and doesn't leave a key what do i do? can i change the lock to get in? where do i stand, have a feeling they wont leave key as this has been an unpleasant scenario with bad feeling please advise on legalities
Your main problem is being sure that the tenant has definitely left - even if you "know" he has gone, it wouldn't be above some tenants to try to trap a landlord into a claim for trespass. Read this:

http://www.landlordzone.co.uk/legal/abandonment.htm