When looking for a long distance carrier, most businesses start by comparing the per-minute rates. While that can work as a first level of comparison, just make sure you are comparing the right rates.

Usually, long distance providers will tout their interstate calling rates. That should be fine if most of your long distance bill is spent on calls to other states. However, if your calls are to locations in your state, you should focus on the intrastate rate instead.

To find the plan that best suits your business, first understand your calling patterns. Examine your last typical phone bill. Break out how many of your calling minutes are for local, domestic long distance, or international phone calls. In addition, take note of other calling services you currently use or will need such as calling cards or toll free calls. You can then take this analysis and apply it against the various calling plans you are considering.

Do not forget other factors - often overlooked - that can have a significant impact on your final bill: common charges, monthly charges, minimum billing requirements and phone directory fees.

Common charges, which are fees that the long distance companies need to pay the government, can often boost your final phone bill quite significantly. While it is required for the carrier to pay these fees, the FCC does not require the carriers to put any charges on your telephone bill. As a result, you will see fees vary. The Universal Service Fund fee typically ranges from 6 percent to 12 percent of the cost of your calls, and the Presubscribed Interexchange Carrier Charge or the PICC fee usually runs about $3 per phone line.

In addition, long distance carriers may charge a monthly fee or require a minimum monthly spending limit in order to qualify for the rates they promote. To be on the safe side, your calling volume should be at least 15 percent above any required minimum to ensure that you get the offered, low per-minute rate.

Finally, telephone directory assistance fees have crept up considerably in recent years. With some carriers charging over a dollar per call, this can be a significant charge if your staff often needs to look up a phone number. Have them use the Internet instead whenever possible to save on fees.

While each plan varies in terms of minimums and fees, I have seen rates as low as 3.75 cents a minute. Be aggressive when it comes to asking for discounts. Some long distance providers will reduce your per-minute rate by 5 percent, for example, if you pay by credit card.

You should also consider additional services you might want. Some long-distance companies offer toll-free service, for example, at no additional monthly cost - you pay only for incoming calls. Or perhaps you are interested in an "accounting" feature, which allows you to code your calls for billing to clients.

Whatever your needs dictate, you should be aware of how the charges will all add up before you make the final call.