Expansion MRR
Expansion MRR is the additional monthly recurring revenue gained from existing customers through upgrades, extra seats, add-ons or higher usage. It is the main way a subscription business grows without acquiring new customers, and it feeds directly into net revenue retention.
Formula
Expansion MRR = sum of positive MRR changes on active subscriptions in the period
How to read it
Count usage-driven increases as expansion too, not just plan changes. Book each movement against the period it was earned for, so a month of heavy usage is not reported as growth a cycle later.