At many growing companies, telecom bills conceal more secrets than an Agatha Christie novel: hidden costs, mystery charges, ancient errors. Here are a few clues for ferreting out costly expenses.

Know your statements. Understand every charge, and watch for changes from month to month. See something new? Ask the provider to explain it.

Take inventory. Once or twice a year, count every line, every service, and every phone. Update the numbers as you grow or downsize; make sure your bills reflect those changes.

Shut off unused lines. Then check future statements to make sure you're no longer paying for them.

Close out ex-employees' accounts. Make sure you're not paying for dormant voice-mail boxes, cell phones, or pagers that, even when unused, continue racking up monthly service fees. Cancel old calling cards.

Scrutinize cellular costs. Shelling out a bundle every month for roaming or off-peak charges? Consider a flat-rate plan; it's usually cheaper and more convenient.

Watch for redundancy. Perhaps you're getting similar services from two providers. Or maybe you're paying one provider twice for the same service. Cancel duplicate offerings; seek refunds for overpayment -- and check your bills to make sure you get them.

Cut pay services. Block calls to 900 numbers; discourage employees from calling collect; encourage them to find numbers online rather than dialing directory assistance. Use prepaid phone cards rather than calling cards, which may charge premium rates.

Be on guard. If you see something strange -- odd calling patterns, exorbitant charges -- check with your provider: a telecom bandit may be hacking into your systems.

Related link:
Cost Cutting: The Money Pit