What it means
An MQL (marketing qualified lead) is a lead that marketing judges ready for sales attention. That usually means they match the ICP and have engaged enough, for example by downloading a guide or visiting pricing. An SQL (sales qualified lead) is a lead that sales has accepted as a real opportunity, typically after a first conversation shows need and timing.
The move from MQL to SQL is the handoff between the two teams. Where the definitions are vague, marketing reports volume, sales reports quality, and the two numbers never reconcile.
How we use it
We define both as dated events in the CRM, so nobody sets them by feel. Lifecycle stages are named after events, and each stage is stamped with the date a record reached it. That makes the MQL-to-SQL rate a number you can trust, and it shows how long the handoff takes.
The scoring gate in our CRM setup checklist decides what qualifies, so two people looking at the same lead reach the same answer.