First of all, versatility is one of the key factors and at the top of the list for many different clients is the kind of emergency services that are offered. Not only does a good London Locksmith company supply 24 hour a day seven day a week services, but they will also guarantee 20 to 30 minute response times when you call them on any different issue.
Make sure they are versatile in another way as well and that means they can look after various issues that you might have whether they are commercially based or have something to do with your home or even your automobile. You might be looking for a locksmith to put in a deadbolt in your apartment one minute but need something done commercially like video inspection equipment the next.
Finally, make sure the 24/7 London Locksmith Services you select have the right credentials as far as training goes. Ask the hard questions and look for a firm that understands the need for updating.