What is geographic routing?

Multi-site businesses lean on it hardest. One advertised number, and the call lands at whichever branch covers that caller's area.

The signal it uses has decayed badly. Mobile numbers keep their original area code forever, so someone who moved from Chicago to Denver a decade ago still dials as a Chicago number.

Number portability did the rest. A business can keep a local-looking number after moving anywhere, which is the point of the feature and the problem for the routing.

Asking is more reliable than guessing. A caller who says their ZIP code gives you better information than any lookup.

Say a pest control company has branches in Austin and San Antonio, one advertised number, and routing by area code. Austin's 512 and 737 go north. San Antonio's 210 and 726 go south.

In a sample week, 90 calls come in. Sixty-seven carry one of those four codes and route cleanly, or appear to. The other 23 have codes from Houston, Chicago, California and elsewhere, because people moved to Texas and kept their cell numbers. No rule covers them, so they all land at the default branch, which is Austin.

Roughly half of those 23 live in San Antonio. Austin's front desk answers, works out where the caller is, and transfers them south. Some of the 67 clean calls were wrong too. A 512 number whose owner moved to San Antonio last year routes to Austin with full confidence. Those errors never reach a report. They show up as transfers and as callers starting with a sigh.

A five-digit ZIP code is a better routing key than any area code, and most callers know theirs without having to think. Build a simple table: each ZIP you serve, and the branch that covers it.

Three edge cases need a decision before you go live. Some ZIPs sit between branches and both could serve them. Pick one owner per ZIP, or you'll have two trucks quoting the same street. Other callers will give a ZIP you don't serve at all. It's better to tell them so on the call than to book a visit nobody can make.

The third case is callers who aren't at the service address. A landlord in Dallas calling about a rental in San Antonio should route by the property. So ask where the work is, not where the caller is.

Blocked caller ID and toll-free callers break area code routing completely, since there's no usable code to read. Asking works the same for every caller, and it costs about five seconds.

GreetKeeper can ask. A caller who states their town or ZIP code has told you where they are, which beats an inference from a number issued years ago.

That detail lands in the summary, so whoever picks the call up knows the location without asking again.

Several branches can sit under one account. Each number can have its own hours, greeting and calendar, so the caller who rang the north branch gets the north branch's diary.