Migrate from Weave to Mailchimp

Mailchimp charges per total contact count across all audiences — duplicate contacts inflate billing

Mailchimp's pricing scales on total member count across every audience in your account. If your Weave migration imports contacts into multiple Mailchimp audiences (by location, by patient type, or by acquisition source), the same contact appearing in more than one audience counts toward your billing limit twice. FlitStack recommends a single consolidated audience with tags for segmentation before migration — this approach keeps your Mailchimp bill predictable and prevents the billing surprise that trips up practices migrating from Weave's flat-rate model.

Weave voicemails, SMS threads, and call logs have no Mailchimp equivalent — only metadata migrates

Weave stores detailed communication histories per patient: voicemail audio files, SMS thread logs, inbound/outbound call timestamps, and duration. Mailchimp is an email-marketing platform — it tracks email open rates and click data per campaign but has no native structure for phone or SMS history. FlitStack migrates the presence of a voicemail (tagged 'voicemail_in_weave') and the last SMS date as reference fields, but the actual audio, transcript, and message content remain in Weave. If your practice requires communication history for compliance or continuity, that data must be archived separately or migrated to a dedicated communication-log platform.

Mailchimp's 40 merge-field limit per audience constrains Weave custom-property migrations

Weave allows an unlimited number of custom properties per contact record. Mailchimp Standard plans allow a maximum of 40 merge fields per audience. Practices with more than 40 custom properties in Weave must prioritize — we recommend migrating only active, segmentation-relevant properties and archiving the rest as a JSON blob in a long-text field or as a separate exported reference file. FlitStack audits your Weave custom-property count during scoping and flags any properties that will exceed Mailchimp's limit before migration begins.

Weave appointment-reminder workflows must be rebuilt in Mailchimp Customer Journey Builder

Weave automates appointment reminders via SMS and phone calls — these triggers fire based on scheduling data in Weave and are tightly coupled to the practice's scheduling system. Mailchimp's Customer Journey Builder can replicate appointment-reminder emails but requires a scheduling data feed (via Zapier, Make, or a direct integration) to trigger messages at the correct intervals. The appointment types, reminder intervals, and patient-segmentation logic from Weave must be mapped manually to Mailchimp journeys post-migration — FlitStack exports the Weave automation definitions as a rebuild reference for your Mailchimp admin.

Mailchimp is not HIPAA-compliant by default — healthcare practices need a BAA

Weave is built for healthcare practices and carries HIPAA-eligible infrastructure. Mailchimp's standard platform is not HIPAA-compliant out of the box — practices handling protected health information (PHI) in their Weave data need to add Mailchimp's Business Associate Agreement (BAA) and configure the account for HIPAA-eligible use. Patient names, appointment dates, and treatment-type data migrated from Weave may constitute PHI depending on your state and use case. FlitStack surfaces this requirement during scoping and recommends confirming with your compliance team before migration.