Canon MF7280 - ImageCLASS B/W Laser Facsimile Manual page 218

Documents cannot be sent overseas (error code #18).
Q Is a pause inserted in the fax number?
A Insert a pause after the country code, or after the fax number of the recipient,
and then dial the number again. (See "Dialing Methods," on p. 2-35.)
A Change the Long Distance setting on the Option screen if you are sending
documents to destinations stored in the Address Book or one-touch buttons.
(See "Storing Destinations," on p. 5-5, or "Storing/Editing One-Touch Buttons,"
on p. 5-24.)
When Problems Occur
8
8-5