help please

Usually this involves signing up for an international calling plan with your service provider.

 

I don't understand what you mean by "setting the phone to roaming". As for making an international call, as Jay mentioned you might want to sign up for a discounted international calling first, otherwise your per-minute rates will be very high. Either way you need to make sure international dialing is not disabled on your account.
To dial the actual number you would either use an international form (+ followed by the country code and then number) or US form of 011 followed by country code and number. Country code for Scotland is 44.

 

Usually the ability to make international calls is on by default. That said it's usually pretty pricey to use the carrier's service to make international calls and that seems to apply both in the US and in Canada. It's much better to use a calling card or a service that specializes in long distance or international long distance who will charge you 2 or 3 cents/minute to make international calls to the UK rather than the ridiculous charges that the carriers want to charge. I use the OneSuite service which has local access numbers all over the US as well as many major Canadian cities (also local access in many foreign countries as well. Also, if you have a smartphone you can use Skype which is very cheap to make calls as well.

Also, roaming (if your carrier roams) in the US and Mexico are usually on by default. It's not cheap, but there it is.

 

Hi Wendy you need to activate your international roaming. There are many companies which provide International SIM card which provides free roaming and low call rates.