Technically calling an 0121 (Birmingham) phone number from any network is not free however inclusive minutes from your EE landline, pay as you go and pay monthly tariff can be used to call these numbers for no extra charge.
Cost of calling 0121 phone numbers
Inclusive minutes from EE can be used instead of paying a financial charge when calling 0121 phone numbers, however this is not technically free as you will still be losing minutes from your balance. This contrasts with true freephone numbers such as 0800 and 0808 helplines which are truly free of charge.
Moreover if you have run out of inclusive minutes you will have to pay EE an access charge and a per-minute fee. These depend on which tariff you are on however landline calls are usually substantially cheaper than equivalent mobile calls, regardless on whether you are on pay as you go or a pay monthly contract, due to their higher access fees.
A short background on Birmingham phone numbers
0121 phone numbers are usually registered to either private individuals on companies in the Birmingham area, as this is the second largest city in the country there are a vast quantity of this type of number in existence. The city used to use the 021 code but under national changes to the area code system this was changed to 0121.