MQL is the inbound lead that has shown sufficient interest to be passed from marketing to sales. Signals: form submission with target attributes (job role, company size), repeated content engagement, downloaded a high-intent asset, attended a webinar.
MQL → SQL (Sales Qualified Lead) is the funnel transition. SQL means the lead is BANT-qualified (Budget, Authority, Need, Timeline). MQLs that don't convert to SQL stay in nurture.
For Indian SMB-targeting SaaS, MQL definition is usually: filled signup form OR booked a demo. The conversion MQL → SQL → customer rates differ wildly: 30-60% MQL→SQL, then 10-30% SQL→customer.