Someone buying a flat in Britain currently faces the prospect of paying £2,845 on service charge per year, analysis of current sale listings has revealed.That comes on top of paying council tax, mortgage repayments, energy bills and in many cases ground rent to a freeholder.But in extreme cases, service charges have become the largest annual cost for flat owners - and they tend to rise over time with costs varying greatly depending on the type, size and location of the property.The annual charge covers things like cleaning in communal areas, repairs, safety checks, buildings insurance, on site staff costs and the managing agents fees. For some apartments, it can also include things like a gym, concierge and a communal garden.Nervousness about high service charges are now putting off some buyers, according to estate agent JLL.In a report last week, it revealed that average service charges on new developments in London have risen by an average of 43 per cent for 'low to moderate amenity' blocks and a whopping 89 per cent for 'high amenity' blocks in the last five years alone. Expensive: The average service charges in London has reached almost £4,000 a year - and in central London it's typically much higherAnd brokers are now warning they are seeing an increase in mortgage applications failing purely due to spiralling service charges.Now, with the help of analytics firm PropertyData, which has analysed Rightmove listings across the country, we can reveal typical service charge bills nationwide and where buyers face paying the most.Where service charges are highest across the UKUnsurprisingly, someone buying a flat in Greater London will pay the highest service charge bill on average.The typical flat on the market in London currently charges a service charge of £3,919 on top of an asking price of £649,299.But while the capital is notorious for having the highest service charges, the costs in other regions look more brutal when looking at it in proportion to the asking price.In the East Midlands, for example, the average flat on the market has a service charge of £1,853 per year against an average asking price of £150,465. That means a buyer will be paying the equivalent of 1.43 per cent of the purchase price in service charge alone.Outside of London, flats currently listed for sale in the North East have the highest service charges on average with annual bills of £2,234, according to PropertyData's analysis.