Nope. You can even create 1-of-2 multisig address and you can also create 1-of-3, 2-of-3 and 3-of-3. What you said is only about 3-of-3. In 2-of-3, for example, only 2 signatures are required to spend Bitcoin associated with it.
I see. Apologies for the incorrect information and thank you for correcting me.
Anytime.
Basically, you can create m-of-n multisig addresses, where n is less than or equal to 20 and m is less than or equal to n. To spend from a m-of-n multisig address, you need at least m out of n signature(s). To know more about the limitations of n, see
http://bitcoin.stackexchange.com/questions/23893/what-are-the-limits-of-m-and-n-in-m-of-n-multisig-addresses.
Note that above detail is about raw multisig address, for P2SH multisig address, values are different. See above link to know more about it.
In Bitcoin-Qt, open the debug console and enter:
createmultisig 1 '["full public key or address in your wallet"]'
It'll give you a "multisig" P2SH address starting with 3 (but requiring only one signature). If you have the private key for the given public key, you'll be able to spend transactions sent to this address, but only using the raw transactions API currently. (You probably want to use
addmultisigaddress instead of
createmultisig if you're actually going to use the address.)
This is regarding Bitcoin core. If you want to test these, I suggest you to use testnet mode to avoid loosing your Bitcoins.
Once you create a multisig address, you can add that address to 'Receiving addresses' list in Bitcoin core by running below command in console.
importaddress address label
Example:
importaddress 3P8qYRHmoybU93bJN9oi1us9XMgYWRV39S BITX