03 numbers are chargeable numbers similar to 08 numbers, introduced in 2007 to allow organisations to offer their consumers a single national point of contact without additional service charges. Rate wise, calls to 03 numbers are similar to calls made to standard 01 and 02 numbers.
Ofcom, the UK’s communications regulator who regulate rates for fixed line telecoms and has capped call charges to 03 numbers from landlines at 9p per minute maximum, and anywhere between 3p to 55p per minute from mobile phones.
FreedomPop is basically a VoIP provider, selling data. Subscribers who pay for the data get unlimited free calls, subject to PUP (Fair Usage Policy) Limits. The basic free package, where subscribers do not pay anything, has a limit of 2300 minutes of calls to any numbers. For all higher plans, where subscribers pay £10.99 or higher, for a progressively higher quantity of data, they also get free unlimited talk time.