trial_ending_soon Event - Upstack Data

Fires when a trial is about to expire (typically 3 days before). Use this event to trigger conversion campaigns and win-back flows.

JavaScript

window._upstack('track', 'trial_ending_soon', {
  accountId: 'acct_abc123',
  trialDaysRemaining: 3,
  planId: 'plan_pro_monthly',
  trialEndDate: '2026-03-04T14:30:00.000Z'
});

Properties

Property	Type	Required	Description
accountId	string	Yes	Account identifier
trialDaysRemaining	number	Yes	Days until expiry
planId	string	No	Trial plan identifier
trialEndDate	string	No	Trial expiration date

When to Fire

3 days before trial expires (common)
When Stripe sends customer.subscription.trial_will_end
When automated warning email triggers

Stripe Webhook

Maps to customer.subscription.trial_will_end.