Are they using their deposit as a last month's rent? What does it say in your lease about using the deposit in this way? The lease I use, which complies with the 2004 tenancies act, states that tenants may not use their deposit as rent. You can download a lease from [broken link removed]if you don't already have one for your next tenants.
Did you point out the state of the carpet / furnishings when you visted the property? Are they prepared to put this right before they leave? It should state in your lease that they have to clean the property before they leave.
It may not be worth your while pursuing - it's very difficult to track tenants when they leave a property - if they leave on bad terms, they don't usually leave a forwarding address.
You can deduct expenses such as carpet / furniture cleaning between lettings from your rental income. Perhaps you would have had to clean these items anyway?
If they have a lease, they would have been obliged to do the following:
- give written notice of 35 days (9 month tenancy)
- not use the deposit as a last month's rent
- make good any damage to property prior to departure
You'll have to really decide for yourself whether it's worth pursuing them - it could have been a much worse situation if they remained in the property and stopped paying the rent.
At least they're agreeing to be out by the end of the month. Make sure you agree a date and time for the handover and tell them you want the place cleaned.