Hi @Jenny26,
I would approach this using two workflows: a deal-based workflow and a contact-based workflow.
The deal-based workflow would re-enroll deals when “Software expiration date is less than 90 days from now”.
The first and only action in this workflow would then be the “Set property value” action.
Before you can set this up, you would first create a new custom contact property called, for example, “Renewal reminder trigger”, a single checkbox. Using the “Set property value” action, you would check this box on the contact(s) associated to the deal.
In a contact-based workflow, you could then re-enroll contacts when this box is checked and use the “Enroll in a sequence” workflow action. After this action, use the “Clear property value” actoin on the newly created custom property so that, theoretically, it could be checked by a workflow again.
When you set this up for re-enrollment, keep in mind that you would each year send the potentially same sequence – which might not be the best experience for your customers.
Let me know if I should provide more detail for any step!