How a call conversion works
Two different mechanisms wear the same name. Calls placed straight from an ad — a call asset, or a call-only ad — are routed through a Google forwarding number, so the platform sees the connection itself and knows how long it lasted. Calls placed from your website are counted by the Google tag swapping the number displayed on the page for a forwarding number, then reporting the same detail back.
In both cases you choose a minimum call length, and only calls that run past it are recorded as conversions. That threshold is the whole point of the metric: it filters out wrong numbers, hang-ups and the person who rang while still reading the page and changed their mind. Set it around the length of your shortest genuine enquiry, not lower.
Forwarding numbers are not offered in every country, and where they are unavailable neither mechanism can work. Check that before you promise anyone call reporting.
Why call conversions matter
Plenty of businesses take most of their real enquiries by phone. A clinic, a trekking operator, a manpower agency or a repair service will get a form fill occasionally and a phone call constantly, and an account that only counts forms will look like it is failing while the phone rings all day.
That gap does more damage than bad reporting. Smart Bidding learns from the conversions you feed it, so an account blind to calls will steadily push budget towards whatever produces forms and away from the searches that produce ringing phones.
Common mistakes with call conversions
The most common is counting a tap on the number as a call. A click on a phone link says somebody intended to ring; it does not say the call connected, or that anyone answered. Two different actions, and mixing them inflates the account.
The second is a threshold set so short that every mis-dial counts, which makes the cost per conversion look excellent and the sales pipeline look empty. The third is number inconsistency: if a forwarding number replaces your real number on the site, but your Google Business Profile, invoices and social pages show something else, some calls go untracked and your NAP consistency suffers too.
Finally, calls to Viber or WhatsApp are not phone calls in this sense. In Nepal a good share of enquiries arrive on messaging apps, and those need their own event rather than being quietly assumed into the call figure.
How to act on it
Decide first what a useful call actually is for your business, then set the minimum length to match it. Make sure someone answers during the hours your ads run — an unanswered phone is a paid click wasted twice. Record the outcome of calls somewhere, even a simple sheet, so you can tell which campaigns produce enquiries that turn into work. Then wire calls in properly alongside your other conversion tracking, and keep the click-to-call event separate from the answered-call conversion.