How much do calls to 03 numbers cost?

The same as calling a normal UK landline (01 or 02) number
Even if you're using a mobile the call only costs the same as calling a UK landline
The cost of the call will even be included in your inclusive minutes
You don't get charged any extra like 0845 or 0870 numbers because we're not allowed to profit from your calls
Read the Official Ofcom website report