I'm afraid to say that airlines apply the excess baggage rules rigidly nowadays and, in the UK, it's expected that up to 4 million travellers will be caught with overweight luggage this year.
Ryanair excess charges are £20 per kg, Thomson Airways - £12 per kg, Monarch - £10 per kg & Thomas Cook - £8 per kg. I haven't mentioned EasyJet, as their allowance is 20kg, unless it happens to be a Thomas Cook holiday using an EasyJet flight, when the Thomas Cook rules apply.
You need to make sure you weigh your case with/on a set of luggage scales before travelling to the airport. Mind you for a holiday in Europe during the summer 15kg is more than enough, in my opinion, when you consider you also have a hand luggage allowance. A lot of people get caught out on the return journey when packing extras like souvenirs, cigarettes & alcohol.
So be careful, stay under and have a great holiday.
Weigh your case to check it is not. If it is more just pay for an extra bag it's around £16 and this will give you an extra 15-20kg. If it is mistakenly over weight as your scales are inaccurate transfer some items in to you hand luggage so as to avoid paying or wear some additional clothes. If it is marginally over weight some airline companies will allow it however, if you are unable to transfer some items out of your case or it is more than just one kilo over they are likely to charge you and this varies in price although it can sometimes be quite hefty. I know regulations vary for different air lines however, i think your allowed 5 kg hand luggage with most airlines and some have no weight restrictions other than size. So take a smallish suitcase as hand luggage. Go to your airlines website and use common sense.
They will charge you extra money for carrying it. Anything from £1 per kilo to £40 per kilo. My son was charged £38 by easyjet for being 2.5 kilo over the 15 kilo allowance only 2 weeks ago. The best thing to do is wear as many clothes as you can. John.
You get charged for excess baggage which can be quite expensive.
on my booking its says weight is 15k what if my case is over