What is the use of the hashtag(#) and asteric(*) on a telephone?

[Dylan]

Why is there a #hashtag and a *asteric on the telephone piece. and i mean the landline and not a mobile phone.

[Carl N]

Hashtag? WTF is a Hashtag? You mean Star and Pound? Asterisk and Octothorpe?

They are used to speed calling or start vertical service features. After you reach a destination, like the bank's IVR, they can be used to back up your input and start over. It lets the system use all the digits 1-0 and still have control codes.

[Rich]

The star key is for various uses, including phone features, and bank or business number inputs.. The hashtag is also useful on many automated systems for navigation of services...(For instance, *67 is used before dialing a number, to hide your phone number.) These are usually called 'pound' (#) and 'star'. (*)

[joe r]

you forgot about the A B C D... * and # are used for special feature codes such as vertical service codes,. *69, *77, *82, 72#, etc... they are also used for automated systems..

A B C D were really only used for the AUTOVON phone system to set priority level of the call... but almost no phones have these digits on them.