When you merge two companies in Brevo, you can now get notified. A new company_merge webhook event fires on every merge, with the ID of the surviving company, the ID(s) of the archived company and the time of the merge. If you sync Companies to your own CRM or data warehouse, you always know where a merged record went.
To set it up, go to Integrations > Webhooks > Outbound webhooks and click Create a webhook. Select “company” from the dropdown, enable the company_merge event and save.