For landlords, any time when your property is not tenanted is bad news. Not only are you not collecting rental income, but you could also still be paying certain costs such as mortgage instalments, ground rent and insurance, as well as council tax, gas and electricity services.

It is therefore critical to minimise void periods where possible, especially if your buy-to-let properties are single tenancy. While the end of all tenancies cannot be avoided - people move on, buy their own home and circumstances change - there are ways to keep tenants for longer and reduce void periods.

Keeping long term tenants

If you are able to form longer-term relationships with tenants, then you will have fewer change overs, naturally reducing rental voids. The key is to make sure tenants are happy, satisfied and keen to extend after a fixed term tenancy.

- Respond to any problems quickly. Arrange repairs or like-for-like replacements where necessary and do it fast. - Be flexible and responsive to specific requests. If good tenants ask for permission to do personalised decorating or want to get a pet, be prepared to accommodate their reasonable requests.

- Keep up with maintenance. If a tenant stays in your property for a number of years it's important that you keep up the general standard of the property. Paint exterior woodwork, keep growing hedges and trees manageable and update fixtures and fittings where appropriate.

- Think carefully before increasing rent. With very long lets it may be necessary to increase the rent you charge in line with market changes. If you decide to do this, make sure you suggest a fair rate that takes into consideration the benefits of having good, reliable long-term tenants.

- Offer longer fixed term tenancy. By requiring tenants to sign up for a minimum rental period of a year you can avoid a series of shorter lets that will cost you time and money, reducing your rental income. Longer tenancy agreements also offer peace of mind and security for your tenants.

How to reduce rental voids

The first void period you will experience (unless you buy a property with tenants in situ) will be on completion of your buy-to-let purchase. After the initial letting, there will be times when you need to find replacement tenants, and these tips for making the process quick and efficient will help reduce your rental voids.

- Advertise ASAP. As soon as your current tenant gives notice to leave start advertising for new tenants. Even when you first buy a rental property and it's not yet ready to let, you can start advertising to get tenants lined up for when work is complete.

- Set the right rent. Research what else is available locally and make sure you are offering a competitive rental rate that will be attractive to potential tenants - and that you are providing value for money.

- Add value. By offering a guarantee that the property will be professionally cleaned and that you will complete any repairs, repainting or replacements before the moving in date, you can start to forge a great relationship with your new tenants.

- Choose the right tenants. Wherever possible, try to select tenants that you know will be happy to call your property home. Also ensure you carry out the correct and thorough referencing requirements. If you have an HMO (House in Multiple Occupation), ensure new tenants are a good 'fit' with the rest of the people in your property to maintain a harmonious house. - Be organised. When you do have a new tenant interested you don't want any hold-ups delaying the start of their tenancy. Make sure you have an efficient system for getting all documents, keys, utilities information and financial checks done.

To maximise your profitability you need to reduce rental voids as much as possible. Being organised and planning ahead can help ensure a quick turnaround of tenants at the end of each tenancy, but it's usually more cost-effective to keep existing tenants for as long as possible.

Remember to offer your tenants a consistently high level of service and support so that if they do decide to leave, it won't be due to anything you did or didn't do!