Not only is London considered one of the most expensive cities in the world, but you might have to open a bank account with a bank in London before you are able to make any major financial commitments in England and London in particular. If you are considering renting an apartment while you are living in London then you may find that London landlords are not too keen on renting to people who only have a foreign bank account. If you are moving to London for work then you can probably get your employer to help you out with getting a bank account organized before you get there. It might also be advisable to find an overseas rental agent who can help you with everything that is involved in moving to London.
Opening a bank account in England is not complicated at all, but you may run in to small delays because you are not a citizen of the country. You will have to have some kind of proof that you are who you say you are, and your passport will usually suffice in terms of an identity document. You will also have to prove that you have permission to be in the country for work. If you are working for a large company then they will have organized all of the paperwork before you start, but it is always a good idea that you make sure that you have the correct paperwork before you leave.
Along with your proof of identity, you will have to take along a letter stating that you are employed here, from your new employer as well as a letter or rental agreement that states your physical address. In some cases, they may need the proof of your physical address in your country of origin as well. Do not worry, British banks stop far short of demanding a DNA sample to open a bank account.
You can, of course, keep using your bank accou0nt in your home country and it may be wise to do so for the first few weeks until you are settled. It is not, however, financially prudent to keep on using a foreign bank account to transact for any length of time as you will be paying a large sum of money every month in fees and in commissions for exchanging money each time you need to make a withdrawal or pay for something.
The banks are usually open every day between 9 am and 5 pm as well as on Saturday mornings. If you are going to open an account be prepared to spend a while getting it all sorted out. It might be best if you make an appointment. If you do not have one then avoid going at lunchtime when it is always busy or at the end of the month.