British pounds to England

If you are going to be in Britain for a few days before needing the money, you could take your daily limit from the ATM every day for three days, which is more than enough for your rent. If it makes you more comfortable, you could order a small amount of pounds to take with you for immediate expenses, too. That way you have some money to use immediately, but won't have the bulk of the cash until closer to when you need it.

ATM is probably your best bet but travellers cheques is still an option.

Unlike the US very few people other than banks accept travellers cheques in UK. You could buy $US traveller cheques and cash them in at a bank in the UK for British Pounds.
The exchange rate will probably be about 5% worse than an ATM, but you may well save in other areas depending on what fees if any your credit card compamy loads on overseas transactions.
Also some UK ATM's charge for use, this should be stated on the machine.

I would not normally recommend an exchange bureau as a sensible way to get foreign currency. However, for London, Thomas Global Exchange will give you a rate that is lower than what many US banks charge for ATM withdrawals. They are currently selling pounds for $1.53610, no commission, no service charges. That is just 1.6% over the current interbank rate of $1.5118/£.

http://www.thomasexchangeglobal.co.uk/
Thomas Exchange Global Ltd, 402 The Strand, London WC2R 0NE
Thomas Exchange Global Ltd , Victoria Branch, 141 Victoria Street, London SW1E 6RA

E-mail them to find out what their policy is on accepting travellers cheques, I don't find it on their website.

Bank of America, Chase, American Express, a number of private companies, and possibly your own bank can arrange an international wire transfer of the funds for a small fee. Knowing most banks, there is likely a fee both for the wire and for the currency conversion but it still might be worth the peace of mind to know that the money has been safely delivered to the owner's account and that you will not have to travel with 900 quid in your pocket. To wire the money, however, your apartment owner will need to be willing to provide some info on his/her bank in Britain.

Call your bank and try raising the daily withdrawal amount.

Diane, when you call your bank to tell them you will be using your ATM and credit cards in the UK (this is something you must do) ask them to temporarily increase you daily withdrawal limit on the ATM. They are almost certain to do that.

As Matt suggested, another alternative is a wire transfer from your account to the owner's account. The owner would need to provide you with the routing number of his/her bank and the individual account number at that bank. You'll pay a small fee if you go into your bank and ask them to do it. Some banks allows their customers to do wire transfers online with no fee. The exchange fee is a wash, since you will pay for that no matter how you move your dollars into pounds. Wire transfers usually move money very quickly.

I can probably do a wire transfer, but I wanted to see the apartment first before giving them money. I don't know the landlords, though they were recommended to me on tripadvisor. I've had several e-mail conversations with them and everything seems fine, but I want to be cautious.

Diane, one solution has been mentioned several times: have your bank increase your limit temporarily. Another point that has not been mentioned so far is that the limit is per card, not per account. If it is a joint account and you are traveling with the joint owner, you can each withdraw up to the limit each day. If this is the case, the time to get the proper amount is reduced from three to two days.

Be aware, though, that the ATM you use might have its own limit that isn't as high as yours. In that case, you might need to withdraw from more than one ATM to reach your personal limit.

I'd take comfort from the fact that you don't have to hand over the money until you've seen the place. A scammer wouldn't do that. But, I'd have alternative or two in place just in case you decide you don't like what you see.

On using two cards: My bank (Bank of America) sent me a duplicate ATM card a few years ago after I was stricken with a bit of paranoia about losing a card while traveling and asked for the duplicate. I have tried using both cards in one day to withdraw over my limit. Doesn't work: One account, identical cards. Your bank may have different rules, but I'd call to make sure.