The easiest (and probably bluntest) way to put it is: if you don't know WHY you need a static IP address, you don't need a static IP address.

Slightly less blunt, the following (pulled from a random website):


When you do NOT need static IP addresses:

If you ONLY do things from the following list, you do not need static IP addresses:

- If you browse the Internet.
- If you send and receive e-mail via an offsite server (the normal method).
- If you download or upload files.
- If you use Instant message services or chat services.

When you need Static IP Addresses:

You need one or more Static IP addresses if any of the following are true:

- You run one or more Web server's directly on your site that require external access (from the Internet, or Extranet but not typically an Intranet) .
- You run one or more E-mail server's directly on your site that require external access (from the Internet, or Extranet but not typically an Intranet) .
- You run one or more FTP server's directly on your site that require external access (from the Internet, or Extranet but not typically an Intranet) .
- You run any other service or 'Application' that requires external access (from the Internet or an Extranet). Some Financial Terminal Client applications require that you have a static IP address for licensing purposes.
- You allow 'incoming' Video Conferencing you may need to use static IP addresses.