Call tracking for Google Ads: counting the calls that were customers
The three layers of call tracking for Google Ads, the minimum duration that separates a customer from a misdial, reading calls, and recording.
By Daniel Stoychev, Webso Digital · 4 September 2026 · 8 min read
If your customers phone rather than fill in forms, an account without call tracking is bidding blind: it sees a click and no result, and Smart Bidding learns that the click was worthless. Call tracking gives the account a conversion for a call that lasted long enough to be a customer, tells you which search produced it, and costs nothing at the basic level, because Google provides the forwarding numbers itself. For a trade, a clinic, a garage or any business where the phone is the till, it is the difference between an account that learns and one that guesses.
The three layers
| Layer | How it works | What it counts | What it costs |
|---|---|---|---|
| Calls from ads | A call asset or a call-only ad shows a Google forwarding number; the call routes to your number and Google records that it happened, how long it lasted and which ad and search produced it | Calls made by tapping the ad itself, mostly on phones | Nothing beyond the click |
| Calls from the website | The Google tag swaps your number on the page for a forwarding number, only for visitors who arrived from an ad, so calls after the click are attributed to the search | Calls made after landing on the page, from any device | Nothing; it is part of the conversion tracking setup |
| A call tracking service | A pool of numbers assigned to visitors by source, with recordings, transcripts, caller details and a dashboard; feeds conversions to Google Ads and GA4 | Every call, from every source, with what was said | A monthly fee, worth it when calls are the business |
The minimum duration, and why around a minute
Every call conversion has a minimum length, and the default is too short. A ten-second call is a wrong number, a hang-up or someone asking whether you are open; a sixty-second call is nearly always a conversation about work. Set the minimum at forty-five to ninety seconds depending on how your calls go, and check it against the recordings if you have them. The point is not to flatter the numbers but to teach the bidding: Smart Bidding optimises towards whatever you call a conversion, and if a misdial counts, it will buy more misdials.
The same logic decides primary and secondary. A qualifying call and a form that arrived are primary conversions; the account bids on them. A short call, a brochure download or a page view can be recorded as secondary for information, and the bidding ignores them.
What GA4 adds, and what it does not
GA4 records a click on a tel: link as an event, and that event can be imported into Google Ads as a conversion. It is better than nothing and worse than a real call conversion, because it counts the tap, not the call: a tap that was cancelled, a tap that reached voicemail and a tap that became a two-hour job all look the same. Use it as a secondary conversion on a small account with no forwarding numbers, and replace it with call reporting as soon as the account is worth the twenty minutes of setup.
Setting it up, in order
- Turn on call reporting in the account settings, so calls from call assets and call-only ads are recorded with duration and source.
- Create a conversion action for calls from ads, with the minimum duration set, counted once, as a primary conversion.
- Create a conversion action for calls from the website, install the call snippet on the landing pages next to the Google tag, and check that the number on the page swaps for a visitor who arrives from an ad.
- Add a call asset to every campaign where the phone matters, with the ad schedule matching the hours it is answered, and consider call-only ads for the emergency searches.
- If calls are most of the business, add a call tracking service, connect it to Google Ads and GA4, and use its recordings to check the minimum duration and to read what customers actually ask for.
- Make a test call from your own phone by tapping the ad and by tapping the number on the page, and look for both in the account the next day.
Reading calls in the report
Once calls are counted, the account can report cost per call by campaign, by search and by hour of day. The hour-of-day view is the one that changes accounts: a business that answers 8 to 6 usually finds a cluster of calls at 7pm going to voicemail, and either extends the hours or moves the schedule. The search view tells you which searches produce calls rather than forms, and those are the ad groups that get call-only ads. The recordings, where you have them, tell you which searches produce customers rather than quotes for work you do not do, which is a list of negatives waiting to be added.
Recording calls: the rule
Recording a business call in the UK is lawful with a proper basis, and the practical rule is to tell the caller: a short message at the start of the call, or a line on the page, that calls may be recorded for quality and training. The recordings are personal data, so they sit inside your privacy policy with a retention period, and the call tracking provider is a processor with a contract. It is not complicated, and the value of hearing what customers ask for is large enough that skipping it to avoid a sentence on the website is a poor trade.
A question for any account that runs on the phone: how many calls came from ads last month, how long did they last, and which searches produced them? If the answer is a guess, the bidding is guessing too.
Questions on this topic
Will a forwarding number confuse my customers?
No. The forwarding number appears only in the ad or, on the page, only for visitors who arrived from an ad, and the call rings your normal line. Your number on the van, the invoice and the Google Business Profile does not change.
Does call tracking work with a mobile number?
Yes. Google's forwarding numbers route to any UK number, mobile or landline. The only thing to check is that the number in the account is the one that is actually answered.
What minimum call duration should I set?
Long enough that a call of that length is nearly always a conversation about work. For most service businesses that is between forty-five and ninety seconds; listen to a few recordings or think about how your calls go and set it from that, then check the conversion count against the calls you actually took.
Can I count calls to my Google Business Profile as ad conversions?
No. Calls from the profile are organic and are reported in the profile's own insights. Only calls from ads and from the website after an ad click are attributed to the campaign, which is as it should be.
Is a call tracking service worth it for a small business?
If most of your customers phone and you spend enough that a wrong bidding decision costs real money, yes, because the recordings tell you which searches produce customers. If you are spending a few hundred pounds a month, Google's own call reporting is enough to start.