Are 0203 numbers free to call?

You can only phone 0203 numbers for free if you have inclusive minutes remaining on your landline or mobile tariff, otherwise you will have to pay your provider a per-minute rate plus an access charge as outlined in their terms.

Local numbers which start with 0203 prefixes are typically registered to personal and business addresses in the UK capital city of London, however you should note that there can be exceptions to this. If you have inclusive minutes remaining on your mobile tariff or your landline package stipulates the use of free calls then you can phone 0203 numbers for free. However if you have neither of these allowances you will be charged a per-minute rate as well as an access charge – these are both normally more expensive for mobile customers compared to calls made from a landline.

Cost of phoning 0203 numbers from a UK mobile (pay as you go)