Most countries will route the call to your number, but it is not guaranteed.
Therefore, OFCOM have introduced 03 numbers.
Calls to 03 numbers cost the same as calls to standard geographic numbers, such as, 01 or 02, even from a mobile phone.
Therefore, using a 0333 number would give your customers confidence in calling as they are cheap to call.
If you are looking to advertise a phone number abroad or expect to receive calls from international callers, please call us on 0800 0016 222 and we will be able to advise you of your best option.
Please note, 03 numbers have become very popular due to the majority of financial, utilities and online companies using them.