Always read the fine print.
While you're responsible for a considerable number of charges in addition to monthly fees, make sure to examine exactly what you're paying for. Every billing statement should provide a detailed summary of your fees; if something looks questionable, contact your vendor.
Essential technical support.
Make sure you know who to contact if you need service assistance after hours (weekends, middle of the night, etc.). You can't afford to lose business because your phones aren't working.
Avoid long-term contracts.
Since prices and plan details change often, long-term contracts can be unfavorable. The standard contract is one year - try to avoid longer contracts. Some companies will include contract language that lets you adjust your rates based on competitive offers, without renegotiating the entire deal. This gives you the benefits of price flexibility without the hassle of switching providers.
Block unneeded charges.
Per-call add-ons like automatic redial, directory assistance, and three-way calling can drive up your costs unnecessarily. Your phone service provider can block these types of services, along with calls to pay-per-minute 900 and 976 numbers, helping you keep your monthly bills free of surprises.
Before you sign on the dotted line, make sure your phone system and computer networks are compatible with a service that combines your voice and data traffic.
Watch your back.
Don't put all your telecom eggs in one basket. Consider getting a backup phone line with another company in event of failure.