Phase 1 — Inventory
- ☐ Pull a 90-day GA4 event report. List every event with non-zero traffic.
- ☐ Pull all custom dimensions and parameters. Note scope (event, user, session) and which events use which.
- ☐ Pull all goals / conversions. Note URL or event triggers.
- ☐ Pull all audiences. Note which ad platforms consume each.
- ☐ List all properties and views (UA legacy if still on UA).
- ☐ Identify all sub-domains and cross-domain tracking patterns.
Phase 2 — Stack mapping
- ☐ Tag manager: GTM / Tealium / Segment / Adobe Launch / direct gtag?
- ☐ CMS: WordPress / Webflow / Shopify / Next.js / static?
- ☐ Data layer: present? structured? documented?
- ☐ Server-side tagging: sGTM / Stape / Cloudflare Workers / none?
- ☐ CAPI integrations: Meta / TikTok / LinkedIn / Google Ads server-side?
- ☐ BigQuery export: enabled? duration? consumers?
- ☐ Looker Studio dashboards: count, who owns them, what they read.
Phase 3 — Compliance
- ☐ DPA in place with current analytics vendor?
- ☐ Schrems II analysis if EU traffic touches GA4?
- ☐ Cookie banner + consent mechanism in place?
- ☐ Consent Mode v2 implemented?
- ☐ Privacy policy mentions GA4 by name?
- ☐ Data retention period documented?
Phase 4 — Risk surface
- ☐ PII in event parameters (email, name, phone)? Find with a 7-day data export filter.
- ☐ User IDs cross-pollinating to GA4? (Critical for HubSpot / Shopify integrations.)
- ☐ Audience dependencies — what breaks if audience refresh stops?
- ☐ BigQuery downstream queries — dashboards, alerts, ML pipelines?
- ☐ Marketing automation triggers reading from analytics events?
- ☐ Attribution models in use (last-click? data-driven? custom MTA)?
Phase 5 — Capacity
- ☐ Who owns the migration? (Single owner is required — committee migrations fail.)
- ☐ Engineering capacity: how many sprint points across how many weeks?
- ☐ Stakeholder communications plan: who needs to know about the cutover and when?
- ☐ Decision criteria documented: what makes the new tool “production-ready”?
Print this checklist. Take it into the audit week. Tick boxes as you go.