If you plan on using a US bank account to make large purchases, you're most likely going to need to initiate a wire transfer. Unfortunately, before your bank will allow you to do this, you need to go into a branch IN PERSON to authorize the service (this has been true for BofA, Wells Fargo, and our smaller CU account, at least). We just found this out, as we're trying to collect the money for our flat deposit and it's basically left us SOL and unable to access our funds except through the ATM (thank god for the BofA/Barclay's agreement and their willingness to raise our daily withdrawl limit).