So you've outgrown your current phone system and need to expand. If replacing your current business phone system is not in the operational budget, there are options for upgrading what you already own.
If you own a KSU system, you may find that expanding your handsets is difficult, as these rarely allow more than a handful of phones to operate off the same line. For Key systems and PBX systems (Private Branch Exchange), however, it's normally just a matter of adding more handsets.
Indeed, Key systems are generally limited to fifty or less lines, so once you close in on the fifty range, you may be limited in your ability to expand. If you have well under that amount, though, you can purchase additional handsets and simply connect them to your main phone terminal or box terminal. Simply find a distributor who carries the phones you currently use and add more to your system. Most modern Key systems will pick up the additional phones once added and only the individual user programming need be dealt with. The end user sets up voicemail, adds call forwarding options and other parameters from the handset itself.
For PBX users, the sky is the limit. You can normally add as many handsets as you require. The advanced call routing abilities of a PBX hub allow you to connect to and share available outside lines. The important thing is to add handsets that are compatible with your current system. Not all handsets are compatible, even if they are made by the same manufacturer. You may be able to find used handsets for your PBX at a discount. These are normally factory or distributor reconditioned and carry a warranty just as new equipment would.
Before you look into a new business phone system, first check to see if your current system will allow you to expand. As opposed to buying a completely new business phone system, it's a lot cheaper and can be performed seamlessly, with no interruption of service to your customers. Ask your business phone system dealer for more information on the options you have with your present equipment and for a recommendation based on your current usage and expected growth.