An 8-xxx number is not necessarily toll-free. The second digit decides who pays.
800 — toll-free
The only code in the 8xx family where the call is free for the caller: the owner of the number pays. Used by support desks, shops and, unfortunately, by telemarketers.
803 — intelligent network services
A service code rather than a subscriber number: used for voting, paid services and content. Charged at a premium rate.
804 — also service numbers
Similar to 803: paid services and interactive menus. A call here is billed at the rate announced in the menu.
809 — premium rate
The most expensive family: paid information and entertainment services. The price per minute is set by the service provider and can be very high.
How to read a bill
Charges for 803, 804 and 809 appear as separate lines. If you see them and did not call, ask the operator to block premium services — the block is free and immediate.
Rule
Only 800 is free. Everything else starting with 8 and a second digit of 0 is either a service code or a paid line.
See also: who calls from 8-800, short numbers and SMS.