Many people think that when you remortgage you will automatically save money. Obviously people would not do it if there was no advantage.
It is important to realise that you may have to pay some charges to remortgage. If you choose wisely, you should be able to end up paying less each month and so the initial costs will be outweighed by that. However, you do need to look into the costs and calculate whether it will be worth it and whether you can afford to pay them.
You may find that your current lender will charge you some money if you are tied in to a contract with them. This is normally if you have a fixed rate. This could be a significant sum of money, especially if you are not that close to the end of your agreement. You will also have to pay charges to the new lender for the searches they will have to do, to ensure your house is worth at least the value of the mortgage. They will want to make sure that if they repossess the house and sell it, they will get back the value of the loan.
They may also charge you a fee for opening the account. This may seem unfair, but they will need to sort out different paperwork. Some lenders will waive one or the other or both of these fees and they will differ in how much they charge you. However, it may be worth paying the higher fees because it could save you money in the long run, if their interest is lower. You will need to calculate this and decide who is the cheapest. It can be a tricky calculation as you cannot predict what interest rates will do over time. You will just have to assume that they will all change at the same rate as the base rates and so will not differ in the difference between them over time. In other words, just assume that the interest rates stay the same and compare them on that basis. There is no way you will be able to predict whether they will react quickly or slowly to changes in interest rates and it may not be consistent over the years anyway.