As well as paying line rental to a telephone provider, many people have some form of call package added on top.
These can be free, or cost an extra fixed amount each month, and will allow you to make some free or reduced-rate phone calls using your phone line.
Most providers now offer an evenings and weekends option, often at no charge or only a few pounds a month, which allows you to make unlimited free calls to 01 and 02 landline numbers in the UK during evenings and weekends.
Look out for the small print on all these deals, as they often stipulate that you must use the phone for less than 60 minutes for each call, or you will incur charges. The simple way around this is to hang up after 55 minutes, and just call the person on the other end back.
The next package up is often an unlimited calls any time package, which allows users to make calls to landlines during the day in the week, as well as the evenings and on weekends. Again, these calls are often subject to a maximum call length.
Other packages vary greatly, and can include reduced-rate calls to mobile phones, or free or reduced-rate calls to international numbers. BT once offered a Friends & Family deal, which other providers have now copied in their own form, that offers reduced-rate calls to a set numbers of your choice.