Most secure = high street bank or building society

Most cost effective = a good currency specialist

Least cost effective = a bad currency specialist

There is no limit but you will find that you are asked for more ID or to use your bank account for larger transactions.

We would like to transfer some US dollar funds from our US bank account into our UK bank account. Can you recommend the most cost effective and secure way to do this - Bank or FX trader? Also, are there any restrictions on the total amount you are allowed to transfer? If there is a restriction, can we increase the amount to be transferred by doing this as a separate husband and wife transaction?