> ## Knowledge Base Index > Fetch the complete knowledge base index at: https://help.nimbata.com/sitemap.xml > Use this file to discover available pages before exploring further. > Pure-Markdown content can be obtained by appending a '.md' suffix to the content URLs listed in the sitemap (without the trailing slash). # Low call attribution rate: how to diagnose and fix tracking gaps in GA4 If fewer calls than expected are showing source, medium, or campaign data in GA4, you have one of two problems: **Capture gap** * Nimbata swapped the number but couldn't read the visitor's session data. * Usually a cookie consent manager. **Integration gap** * Nimbata captured full session data, but it never reached GA4. * Usually a Client ID or workflow misconfiguration. They look the same on the surface but require different fixes. Diagnose which one you have first. ### Step 1. Check Nimbata's attribution data * Go to [Activity > Calls](https://app.nimbata.com/activity/calls). * Open an unattributed call. * Check the **Attribution** section of the call record. Source and medium are populated > data was captured but didn't reach GA4. **This is an integration gap. Go to Section A.** Source and medium are empty > session data was never captured. **This is a capture gap. Go to Section B.** # Section A. Integration gap: call data not reaching GA4 ### A1. Verify your GA4 credentials * Go to [Integrations > Google Analytics](https://app.nimbata.com/integrations/google-analytics) in Nimbata. * Confirm the **Measurement ID** (format: `G-XXXXXXXXXX`) matches exactly the one in GA4 under **Admin > Data collection and modification > Data streams > [your stream] > Stream details**. * Confirm the **API secret** comes from **Measurement Protocol API secrets** on that same screen; not a Tag Manager token or any other credential. * Confirm the integration status shows **running in 1 workflow**. | A single mismatched character in either field will silently block all events from sending. ### A2. Check whether the Google Client ID is being transmitted Nimbata links call events to GA4 sessions using the visitor's `_ga` cookie. If it isn't captured at call time, GA4 can't match the event to a session; even if source and medium are correct in Nimbata. * In a call record, check for a **Client ID** field in the attribution data. * If it's blank on calls that do have source and medium, the Client ID handshake is broken. Common causes: the Nimbata script loads before GA4's `gtag.js` initializes, the `_ga` cookie is blocked by a consent manager, or a GTM error is preventing the GA4 tag from firing. **Fix:** in GTM, set your GA4 configuration tag to fire on **All Pages** with no conditions, and ensure the Nimbata tag fires after it. ### A3. Check your workflow configuration * Go to [Workflows](https://app.nimbata.com/workflows). * Open the workflow driving your GA4 integration. * **Trigger:** must be set to **Call ends**, not Call starts. * At call start, duration is 0; any duration filter will fail. * **Filters:** check every condition. * A common silent blocker is **Recording = Yes**. * If a caller presses the privacy opt-out digit, recording stops and this filter fails. * Replace it with **Duration > X seconds** instead. * **Status:** Confirm the workflow is enabled and showing as running. ### A4. Check for GA4-side data filters * In GA4, go to **Admin > Data filters**. * Confirm no filter is excluding events sent via the Measurement Protocol. # Section B. Capture gap: session data missing at the point of the call ### B1. Check whether a consent manager is blocking the script This is the most common cause, especially in markets with low opt-in rates (Germany, Sweden, France, Poland). The pattern: DNI is working and numbers swap when tested, but a high percentage of calls from a specific market show no attribution. To confirm: * Open the affected site in a fresh browser session without accepting the cookie banner. * Call the tracking number and check the resulting call record in Nimbata. * If source and medium are blank, repeat the test after accepting cookies. * If attribution appears after accepting, the consent manager is the cause. **Fix:** review how your consent manager categorizes the Nimbata script and GA4 tag. If compliant with your privacy policy, moving Nimbata to a **Functional** or **Necessary** category will resolve this. Ensure the GA4 tag fires before Nimbata even in consent-pending mode, so the `_ga` cookie is set first. ||| Consult your legal team before changing cookie categorization. ### B2. Check the script load order Even without a consent manager, if Nimbata fires before GA4 it cannot read the `_ga` cookie. * Open **F12 > Network.** * Reload the page. * Confirm the GA4 tag fires before the Nimbata script. * In GTM, add a trigger dependency or sequence the Nimbata tag after GA4. * In manual installs, place the Nimbata script tag below the GA4 tag. ### B3. Check that your swap group source matches your traffic * A **Google Ads** swap group only swaps for visitors with a `gclid` parameter. * Calls from other channels won't have campaign attribution. * An **All Visitors** swap group swaps for everyone but will show many calls as direct or organic. Confirm your swap group sources match your attribution expectations. ### Realistic attribution benchmarks * **60-80%** is typical for single-market setups with moderate consent rates. * **Below 50%** usually indicates a fixable technical issue covered in this guide. * **Near 0% in one market** with a working setup elsewhere is almost always a consent manager or script load order issue. --- Detailed Guide: [**Google Analytics 4 integration: how to set it up in Nimbata**](https://help.nimbata.com/en/article/google-analytics-4-integration-how-to-set-it-up-in-nimbata-1l4tjvt/) Detailed Guide: [**Google Ads conversions via GA4: how to import Nimbata call events**](https://help.nimbata.com/en/article/google-ads-conversions-via-ga4-how-to-import-nimbata-call-events-15fwxe6/) Detailed Guide: [**How to set up your first workflow**](https://help.nimbata.com/en/article/how-to-set-up-your-first-workflow-q8c5v5/) Troubleshooting: [**Tracking number not swapping: full troubleshooting guide**](https://help.nimbata.com/en/article/dni-full-troubleshooting-guide-10-reasons-why-numbers-are-not-swapping-on-your-website-dfo4sa/)