Tracking number on your Business Profile phone: worth the NAP risk?

Local service folks, does swapping your Business Profile phone number for a tracking number actually help, or does it just muddy things?

Take a plumbing business that wants to know how many calls come from the Maps listing versus the website and ads. A tracking number on the listing would answer that. But Google already reports calls from the profile, so you may not need one. A swapped number also creates NAP problems if the old one is still on directories, and anyone who saved your real number stops reaching you.

My take is to put tracking numbers on the website and ads and leave the main Business Profile number alone, unless you have a second line you can afford to lose. Has anyone run it the other way and seen a clear difference?

Google's call numbers aren't enough on their own. They only count calls placed through the listing, so anyone who saved your number years ago and dials it from their contacts never shows up. That's a real blind spot, but it's no reason to swap the number. I'd never change the number people already have on the profile. Treat Google's call data as a trend line, and only add a second number if you're willing to track it for a few months before drawing any conclusions.

Agreed on the blind spot, but I'd keep the rule simple: never change a number that's already public, and only put tracking numbers on channels you create, like the website and ads. For whatever's left, like callers who found you through a saved contact, just ask "how did you hear about us?" on every call. It's rough, but it catches the people Google's data misses, and it costs nothing to run.

The how-did-you-hear question breaks down with the saved-contact crowd. If someone's been dialing a number they've had for years, they almost never remember where they first found you, so the answer drifts into "word of mouth." I'd treat that bucket as unknowable and judge ads by whether total call volume moves when spend changes. Have you ever paused a campaign and watched the calls?