Call tracking · Offline conversion tracking
Every phone call, traced to its ad.
Proofbell tells you which campaign, ad and landing page produced every phone call — then sends the revenue that call became back to the platform that earned it.
Free, with no card and no time limit — the tag and your web traffic attributed. A tracking number comes with a paid plan from £29 a month.
Running this for clients? Proofbell for agencies.
- Know which ad made the phone ring
- Bid on revenue, not form fills
- Every call carries its campaign
- Numbers you can defend in a meeting
Fig. 01 · The gap
Half your best leads never touch a form.
For a considered purchase — windows, legal advice, an emergency callout — the serious enquiry is a phone call. Someone with a real budget and a real deadline picks up the phone rather than typing into a box.
Your analytics sees the click and then stops. The call happens in a different system, the sale happens weeks later in a third, and nothing joins them up. So your ad platform optimises towards the leads it can see, which are the cheaper, lower-intent ones.
Campaigns that produce your best phone enquiries look like your worst performers.
Smart Bidding learns from form fills only, so it buys more of the wrong traffic.
You cannot tell a £40,000 enquiry from a wrong number, so every call counts the same.
Reporting to a client means asserting the marketing worked, with nothing to show.
Fig. 02 · Installation
Three steps, then it runs itself.
Setup takes about ten minutes. Nothing about how you answer the phone changes.
- Step 1
Add one line of script
The tag swaps the phone number on your site for a tracked one, per visitor. Your real number stays visible if anything fails — a tracking script must never cost you a call.
- Step 2
Calls arrive with their history attached
Channel, campaign, landing page and — where the platform reports it — the keyword. The call rings your normal phone; nothing about how you answer changes.
- Step 3
Send the outcome back
When a call becomes a quote and then a sale, import the value from your CRM or a spreadsheet. Proofbell pushes it to Google Ads so bidding optimises on revenue, not on raw call volume.
The failure modes, the number-matching rules and what the tag records are on How it works.
Fig. 03 · The record
One call, one row. Nothing summarised away.
This is what the call log shows. Every figure in it is a sample and is marked as one. The columns are not.
| Campaign | Landing page | Keyword | Length | Summary | Value |
|---|---|---|---|---|---|
| Search · Conservatories Glos | /conservatories/ | conservatory cost gloucester | 6m 12s | Wants a quote for a 4m lean-to before spring. | £8,400 |
| PMax · Windows | /windows/upvc/ | not reported by Google | 2m 48s | Asked about triple glazing on a 1930s semi. | not yet |
| Meta · Retarget 30d | /quote/ | n/a | 0m 09s | hang-up · not billed | £0 |
| Organic · Google | / | not reported | 4m 31s | Existing customer, roof lantern leak. | £2,150 |
| Search · Brand | /contact/ | proofbell reviews | 0m 41s | flagged spam · not billed | £0 |
Fig. 04 · Attribution
Six models side by side, and one that admits doubt.
Seeing the models disagree is the point. It tells you how much of a channel's performance is a modelling choice rather than a fact. On Scale a Markov model derives credit from your own data instead of a rule someone picked, reports a confidence interval instead of inventing a ranking, and says so when two channels are too close to separate.
- First click, last click, last non-direct, linear, time decay and position based
- Credit computed when you ask, never baked in — flip the model and see the difference
- On Scale, Markov attribution learned from your own journeys, with confidence intervals
- Every report carries a reconciliation line that must come to zero
Every paid plan transcribes the call
From £29 a month, with a short summary, the overall tone, the topics raised and what the caller seemed to want — worked out by the same supplier that produces the transcript, so no further company gets a copy of your calls. No language model reads them: nothing scores an agent or rates a call, and we would rather say so than imply it.
Recordings, with permissions that make sense
Recordings are encrypted at rest. Listening and seeing deal values are separate permissions, so a client can see their return without hearing their customers' calls.
Tell a person, or tell a system
Alerts reach email on every paid plan and Slack from Growth, carrying the caller's number only if you switch it on — never the recording or the transcript. From Growth a signed webhook can send the same call to anything that accepts a POST, with a delivery log when one fails. API keys from Pro.
Revenue in, conversions out
Import closed deals by CSV and match them to the calls that started them; every unmatched row is explained rather than quietly dropped. The value then goes back to the ad platform, so bidding optimises on revenue rather than on raw call volume.
Dynamic number pools, sized honestly
We tell you how many numbers you actually need from measured concurrency — and when keyword-level tracking cannot work for your traffic, we say so instead of selling you numbers.
Each connection states how far it has been verified
Google Ads is live. Microsoft Advertising, Meta, GA4 and LinkedIn are built, and each says on its own card whether it has been proven against the real platform — so a tick means what it says. The gaps are on the features page with the same prominence.
Fig. 05 · Revenue in, conversions out
- Google Ads · live
- Microsoft Advertising · built
- Meta · built
- GA4 · partial
- LinkedIn Ads · partial
- HubSpot
- Salesforce · not connectable yet
- Xero · not connectable yet
- Slack alerts · from Growth
- Signed webhooks · from Growth
- CSV import
Live means proven against the real platform. Built means the code exists and has not yet sent a real conversion; partial and not-connectable are named as such. Every one of these appears on Features with the same label and the same prominence, because you would find the gaps anyway.
Evidence, not enthusiasm
Measurement is easy to make confident and hard to make true. Where the data cannot answer, we would rather say so.
Fig. 06 · Reconciliation
Measurement you can defend in a meeting.
The hard part of attribution is not producing a number. It is producing one you are still confident in when a client disagrees with it. Fractional credit means totals can drift, so every report carries a line that must come to zero. Where the data cannot answer, we would rather say so than invent a ranking.
You will check our numbers against your own. You should. The line is there for it.
Fig. 07 · Price
Published, bought online, no sales call.
Billing is per answered call, never per minute. The higher tiers, every overage rate and a calculator that prices your month are on the pricing page with the same clarity.
The tag and your web traffic attributed, on a free account with no time limit. It includes no tracking number, so it tracks no calls: paying is what buys the first number.
- The tracking tag on one project
- Your web traffic attributed — sources, campaigns and landing pages
- Last-click attribution on web sessions
- The dashboard and the reports that read web sessions
One business, one number, one website. The first paid tier buys the tracking number, and with it the calls, their transcripts and the conversions pushed back.
- 1 tracked number included, swapped per visitor
- 125 answered calls a month, then per answered call — hang-ups and flagged spam never billed
- Last-click attribution
- Every answered call transcribed, with sentiment, topics, caller intent and a summary
- Email alerts
- Offline conversion import from CSV, pushed to Google Ads
Growth, Pro and Scale, the overage rates and the month calculator are on the pricing page
Objections
Questions worth asking
Including the ones where the honest answer is "no".
Will this change how my phone rings?
No. The tracked number forwards to your existing line, so you answer the same phone in the same way. If our system were ever unreachable, the tag leaves your real number on the page — a tracking script must never cost you a call.
Do I need to change my website?
One line of script in the head, the same as any analytics tag. It finds phone numbers in your page and swaps them, keeping your original formatting so the page looks untouched.
Can you tell me the exact keyword someone searched?
For Google Search campaigns, usually yes. For Performance Max, Shopping, Display and Demand Gen, no — and neither can anyone else, because Google does not report keyword data for those clicks at all. We show you which of your traffic can carry a keyword before you pay for the numbers to track it.
How is this different from just using Google's own call reporting?
Google can tell you a call happened from a Google ad. It cannot tell you the call became a £14,000 order six weeks later, or attribute a call that arrived through organic search, or compare the two. Sending real revenue back is the part that changes what Smart Bidding buys.
Do I get a transcript and a summary?
Yes, on every paid plan — transcription is included from £29 a month rather than sold as an upgrade. With the transcript you get a short summary, the overall tone of the call, the topics that came up and what the caller seemed to want. They are worked out by the same supplier that produces the transcript, from audio it already has, so no further company receives a copy of your calls. What you do not get is a language model reading them: nothing scores an agent, rates a call or applies your own tags, and that is not built rather than coming soon. Transcription stays off until you turn it on for a project, and it is unavailable on an account that has declared it takes special-category calls.
What happens to call recordings?
They are encrypted at rest and stored in the UK/EU. Access is a separate permission from seeing deal values, so an agency can show a client their return without giving them the ability to listen to their customers' calls. Recording is optional per project. The retention period is fixed on Essential and Growth — 30 and 90 days — and settable up to 730 days on Pro and Scale. You can always shorten it.
Can it notify my team when a call comes in?
Yes. A rule says what raises the alert — a call answered, a call finished, a call missed — and can be narrowed by talk time, by whether it is that caller's first ever call, and by the marketing channel it came from. Alerts go to email on every paid plan, and to a Slack channel from Growth, where a rule can mention the people who should see it. An alert carries the marketing source, the tracked number and a link into the dashboard; it never carries the recording or the transcript, and it carries the caller's number only if you switch that on. To tell a system rather than a person, a signed webhook does the same job from Growth. On the free tier a rule saves and then waits for ever: with no tracking number, no call can arrive to trigger it.
Am I billed for wrong numbers and hang-ups?
No. Billing is per answered call, and calls under ten seconds or flagged by spam scoring are excluded. Per-minute pricing — which most call tracking uses — charges you most for the long enquiries that are actually worth having.
How long until it tells me something useful?
Channel and campaign attribution works from the first call, on every paid plan. Data-driven attribution is on Scale, and it also needs volume — around 100 customer journeys and 20 conversions — with Proofbell telling you it is not ready rather than showing you a model fitted on too little data.
Is this GDPR compliant?
It is built to be used compliantly: UK/EU data storage, encryption at rest, configurable retention, an audit trail of who accessed what, and a strict-consent mode that withholds data from ad platforms until consent is given. You remain the data controller; we act as processor, and we will sign a DPA.
What if I want to leave?
Cancel from the billing page and you keep access to the end of the period you have paid for. Your data is exportable while your account is open. Recordings and transcripts are kept for 30 days after that and then deleted — we email you the date first. Number porting is not automated: if you need to take a tracked number with you, ask us and we will arrange it with the carrier rather than pretending there is a button. How long that takes is set by the carrier receiving it, so we get you a date in writing rather than guessing at one.
Free plan · no card · no time limit
Find out which campaigns are actually ringing.
Install the tag on a free account and watch your web traffic attribute itself to the campaigns that produced it. Add a plan when you want a tracking number, and the calls arrive with the campaign already attached.