Google Tag Migration

Google Tag migration is required whenever your current tracking architecture no longer matches the capabilities or requirements of your measurement goals. The most common migration scenarios we handle are: Universal Analytics to GA4 (the fundamental migration that should have been completed before UA's sunset in July 2023, but many businesses still need to retroactively address properly); legacy gtag.js to GTM-managed Google Tag (to gain the governance and flexibility benefits of GTM); client-side GTM to server-side GTM (to improve data accuracy in a consent-restricted environment and reduce reliance on client-side tracking); and custom tracking implementations to standardised GTM-managed configurations. Each migration scenario requires careful planning to maintain data continuity, avoid temporary measurement gaps, and ensure the destination implementation is correctly configured before the source is decommissioned.

Our Google Tag migration service begins with a pre-migration audit of your current implementation — documenting every tag, its configuration, its data quality, and any known issues. From that baseline, we design the migration architecture: what the destination configuration should look like, which elements of the source implementation should be replicated versus improved upon, and what the go-live sequence should be to minimise measurement gaps. Migration work is executed in a GTM workspace that can be reviewed before publication. For GA4 migrations from UA, we include a pre-migration GA4 baseline configuration period to accumulate historical data before UA is retired. Post-migration, we run a parallel verification period where source and destination data are compared for consistency before the source implementation is decommissioned.