GCLID call tracking

What is a GCLID?

A GCLID (Google click identifier) is a unique code Google adds to your landing page URL when someone clicks an ad, as long as auto-tagging is on. It looks like ?gclid=Cj0KCQjw…. Google's auto-tagging help explains how it is added.

The GCLID tells Google exactly which click, keyword, ad and campaign a conversion came from. For forms, the Google tag reads it automatically. For phone calls, something has to keep it until the visitor rings, and that is the call tracker's job.

On some iOS traffic Google uses GBRAID or WBRAID instead of a GCLID. Call Bullet stores these in the same way.

How does GCLID call tracking work?

It links three moments: the click, the visit and the call.

1. A searcher clicks your ad and lands on your site with a GCLID in the URL.
2. The Call Bullet swap script reads the GCLID, starts a session and shows a number from your website pool.
3. The visitor browses and rings the number shown, perhaps minutes later.
4. Call Bullet sees which session holds that pool number at that moment and attaches the GCLID to the call.
5. The call is recorded and transcribed, and checked against your counting rules.
6. Qualifying calls are uploaded to Google Ads with the GCLID, call time and value.

Why do I need a number pool for GCLID tracking?

Each concurrent visitor needs their own number so the call can be matched to the right click.

If two ad visitors see the same number at the same time and one rings, there is no way to know which GCLID belongs to the call. A pool gives each active visitor a different number for the length of their session. When the session ends, the number returns to the pool.

The size of pool you need depends on how many ad visitors are on the site at once. A local trades business might need four to six numbers; a busy national site needs more. Read session-based number pools and visitor-level call tracking for sizing.

What can go wrong with GCLID call tracking?

Most failures are setup issues you can check in a few minutes.

Upload errors are covered in importing call conversions to Google Ads.

Does GCLID call tracking work with cookie consent?

Storing a click ID and session for attribution is generally treated as analytics or advertising storage, so under PECR it should respect your cookie banner choices.

Call Bullet reads the GCLID from the URL and keeps it with the visitor's session. Configure your consent setup so tracking runs only where your legal advice says it should, and explain call tracking in your privacy notice. When a visitor declines, they still see a working number; the call is simply not matched to a click.

How is GCLID tracking different from source-level tracking?

Source-level tracking tells you a call came from Google Ads. GCLID tracking tells you which click, keyword and campaign, and lets Google credit that click in its own reports and bidding.

That is why GCLID tracking is required for offline conversion import for calls. Static numbers on an ad or a print advert only give source-level data. See calls from ads vs calls from website for how the two routes differ.

How do I check my GCLID tracking is working?

Click one of your own ads from a phone (avoid clicking repeatedly to protect your budget), or add ?gclid=test to a landing page URL to check the swap. The number on the page should change to a pool number. Ring it, and the call should appear in Call Bullet with Google Ads as its source. The Google Ads validation check then confirms Google accepts a real upload without counting it.

How does Call Bullet keep the GCLID across several visits?

Call Bullet keeps the most recent ad click with the visitor's session so a later call can still be credited.

Many people do not ring on their first visit. They click an ad, read your prices, leave and come back the next day by typing your name or using a bookmark. If the click ID were lost when they left, the eventual call would look like direct traffic and Google would never learn that the ad worked.

The swap script stores the click ID with the visitor's session on your domain. When the same visitor returns and rings a pool number, the call is matched back to the stored click as long as it is still inside the conversion window. The Calls page then shows the full journey, including the landing page and the source of each visit. Read keyword-level call tracking for how keywords are shown alongside the click.

If the visitor clears cookies or switches device, the link is lost, which is one reason Google's figure and yours will never match exactly.

Which click IDs does Call Bullet capture?

Call Bullet captures every Google click identifier that can be used for a call upload.

Whichever ID arrives, it is stored with the visit and uploaded with the matching call, so iOS ad visitors are credited too.

Frequently asked questions