I'm trying to call a clinic in Moreton from the US:
0844 477 2577
I'm dialing 011 44 844 477 2577 and getting a message that the call will not go through. Am I doing something wrong? Thanks

the prefix you are adding is correct - but I think that the area code part (0844) must be a "premium" number or similar service that will not work outside the UK. Have a search for an alternative number (not starting in 08).

I just googled the number and the result then reveals that people calling from abroad should call 01144870 1127570
HTH

Numbers beginning with 8 are for special payment rates (844= 5p per minute), so maybe this doesn't work for calls from abroad.

Their webpage (http://tinyurl.com/2xv2yc) says

"Phone Number from Abroad: 0870 1127570"

That explains it. Thanks Phil and Patrick for your help.

Try dialing 00 44 844 477 2577

It doesn't apply in this case, but there is a website called SAYNOTO0870.COM
http://saynoto0870.com/

It's not the most elegant of websites, but if you click on "Search to find an alternative number" at the top on the left, you can type in the premium number and it will give you the equivalent geographical number which will be much cheaper.

I have used it myself. It doesn't list all companies but enough to make it a very valuable resource.