If you said, "A couple of months," you're wrong.

If you said, "A year," you're wrong.

How about 18 months? Nope, not long enough.

That's a lesson I learned the hard way. We got a call yesterday from a customer who wanted to know the status of their order. It was a customer who's previously placed a number of orders with us for various products. They've always gotten their orders promptly, so they were suprised that their latest order hadn't arrived yet.

Because they do order from us several times a year, they didn't call in their order. They just faxed over a purchase order, and assumed it would be filled quickly as it always had been in the past.

And it would have been - except I had cancelled the fax line they called, and we never got the purchase order.

You see, the number they dialed was an old fax line -- One we haven't published in almost two years. It hasn't been on our business cards or our website in almost two years, and it's never been on any of our products. I've had it call-forwarding calls to our current fax number ever since we changed it a couple of years ago.

So, it seemed safe to cancel the old number. I forgot to ask the phone company to alert callers the number had changed, and I also forgot that customers don't go on the web to check fax and phone numbers. They just flip to whatever they use as a contact manager and dial the number.

Fortunately, I hadn't cancelled the old voice phone number, so the customer was able to reach us. But I can't help wondering how many orders we've lost since that fax number was cancelled.

Moral: before you cancel old phone or fax numbers, consider whether anyone might still be using them to reach you and place orders.