What Enhanced Conversions does
Enhanced Conversions sends hashed first-party customer data - email, phone number, name, or address - alongside a standard conversion event, giving Google Ads a second, privacy-preserving matching signal beyond click ID and cookies. As cookie-based matching degrades, this hashed-data signal is what keeps conversion measurement and bidding-algorithm training intact.
Setup via Google Tag Manager
The most common path: configure Enhanced Conversions on the Google Ads Conversion Tracking tag in GTM, either using GTM's built-in Enhanced Conversions field-mapping (reading form field values or a data layer variable) or, for a more reliable implementation, sending the hashed data server-side through a server-side GTM container.
Setup via GA4
If your Google Ads conversions are imported from GA4 conversion events, Enhanced Conversions can be enabled at the GA4-to-Google-Ads link level, using the customer data GA4 already has in its user-provided data collection settings. This path is simpler when GA4 is already your source of truth for conversion events, but is dependent on GA4's own data collection being complete and consent-gated correctly.
Offline conversion upload to Google Ads
Separate from Enhanced Conversions, offline conversion import solves for conversions that happen after the click but outside any web session - a sales-qualified lead that closes two weeks later, for example. It requires capturing the GCLID (Google Click ID) at the original lead-form submission, storing it against the CRM record, and uploading the conversion (with the GCLID) back to Google Ads once the offline event occurs. This is the mechanism that lets a B2B sales cycle feed Google Ads' bidding algorithm real revenue signal instead of just lead-form submissions.
Consent handling
Enhanced Conversions and offline conversion data are both customer PII in hashed form - both should be gated on recorded ad-storage/analytics-storage consent state (Google Consent Mode) before being sent, not sent unconditionally because the data is hashed.
How to verify it worked
- In Google Ads, open the conversion action -> Diagnostics, and check the Enhanced Conversions status and match rate
- Use GTM's Preview mode or GA4 DebugView to confirm the hashed customer parameters are actually populated on the conversion event, not blank
- For offline conversions, confirm the GCLID is being captured and stored at lead-form submission, then confirm the upload shows in Google Ads' offline conversion upload status with no rejected rows
- Cross-check Enhanced Conversions match rate against your known first-party data completeness - a match rate far below your form-fill data quality usually points to a hashing or field-mapping error