Hi, this could be a loose meter cable or somethings come loose in the consumer unit. Or over the Christmas period you may have used quite a bit of power and could have eventually blown the main fuse to the flat. Depending on the size of the flat will depend what rating it is. Either a 60, 80 or 100amp. Most probably a 60amp if it has blown. It's easy to rectify, the fuse itself costs less than £10. And it take s less than 10 minutes to change it. However it might be beneficial to book in a test on the electrical system to dismiss any latent defects that may have contributed to the fault. The bs number for the main fuse is bs1361 type 2 (b). Instead of asking an expert simply add your job on rated people then a local electrician will contact you shortly to arrange a repair. To give you an idea of cost, the test should cost less than £150, and if the fuse has blown you should expect to pay less than £50 to install a new one. Maybe under £30 if the electrician is in a good mood. I may be way off as mentioned previously and without looking at the fault, you may have another issue causing the power failure. The breaker box for the flats may have tripped also. Can't really diagnose fully without an inspection obviously. Regards Alfie Hants Electrical Fareham. To find me Google Hants Electrical fareham.