best place to change £ to $?

My mom was just here and I will warn you - don't let them get traveler's cheques before they come!!! My mother had a heck of a time trying to use hers (they were indeed in £'s).  We ended up going to my bank (Nationwide) and depositing them into my account and I took out the cash for her.  The only reason the hotel would take her travelers cheques was because I was local and they knew me, otherwise they said they normally would not take them.

My brother was relying on cashpoints - but he could only use Alliance & Leister and Royal Bank of Scotland to take out cash.  Tesco - Natwest - Nationwide - Lloyds all came back with "service unavailable" warnings.

All of this was two weeks ago, so this information is current.

If they are able to use cashpoints - it is the best exchange rate.

My mom was just here and I will warn you - don't let them get traveler's cheques before they come!!! My mother had a heck of a time trying to use hers (they were indeed in £'s

Argh! You are SO right. My family has been and gone but lemme tell ya, my Mom and I went to a lot of effort to give everyone the info they needed. So we told them that cash points were THE best bet.

So what do half of them do? Bring traveler's checks in DOLLARS and a wad of greenbacks!!

I felt like we spent WAY too much time wondering where to exchange the next lot of checks or cash. And at crap rates, too.

Urgh! 

BTW, welcome to the site!

Where is the best place to cash an American Express travelers check in the UK? Some have mentioned the post office.
I want to avoid as much fees as possible.