What are MQL and SQL? The marketing-sales lead handoff and SLA

A "lead" isn't one thing. Someone who downloads an e-book from your site and someone who browses the pricing page three times and requests a demo aren't at the same maturity. To manage this difference, the marketing and sales world uses two concepts: MQL (marketing qualified lead) and SQL (sales qualified lead). And the place most leads get lost is the handoff between these two — marketing says "we gave you leads," sales says "they were low quality," and qualified prospects fall through the cracks.

This article covers what MQL and SQL are, their difference, the handoff process, the SLA that fixes it, and how to manage it all with a CRM.

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What is an MQL?

An MQL (Marketing Qualified Lead) is a lead that has shown enough interest through marketing activities to be a candidate for handoff to sales but isn't yet mature enough for sales to engage. What makes a lead an MQL is its behavior: signals like content downloads, opening emails, visiting the pricing page. These signals are usually measured with a lead score; when the score crosses a threshold, the lead moves from "marketing-ready" to "handoff-ready."

What is an SQL, and how does it differ from an MQL?

An SQL (Sales Qualified Lead) is a lead the sales team has reviewed and confirmed is genuinely an opportunity. An MQL is a marketing guess ("this person looks interested"); an SQL is sales' verification ("yes, this is a real buyer worth pursuing"). The difference is critical: not every MQL becomes an SQL. Sales evaluates the handed-off MQL with qualification criteria; if it fits, it's promoted to SQL (and an opportunity); if not, it's returned to marketing with a reason.

The handoff: where leads leak most

The move from MQL to SQL is the moment marketing and sales shake hands — and in most organizations this is the most fragile point. Marketing throws the lead over but sales doesn't touch it for days; or sales ignores it as "low quality"; or nobody knows who owns the lead. The result: the most expensively gathered qualified leads cool and disappear right when their interest peaks. This leak can be closed far more cheaply than gathering more leads.

SLA: tying the handoff to a commitment

What fixes the handoff is a written SLA (service level agreement) between marketing and sales. The SLA is two-way: marketing commits to how many qualified MQLs it will supply a month and which criteria they'll meet; sales commits to how fast (say, within the first business day, or even the first few hours) it will touch each MQL. This turns the "quality leads vs fast follow-up" argument into a measurable agreement. The SLA's power is that it aligns the two teams in one funnel; we covered this alignment in full in sales-marketing alignment.

Managing MQL→SQL with a CRM

The MQL and SQL concepts only work if they live in a CRM. When the lead score hits the threshold, the CRM automatically marks the lead an MQL, assigns it to the right sales rep and records the handoff time. Whether sales promoted the lead to SQL or returned it with a reason — it's all tracked. So "how many MQLs were given, how many became SQLs, how long did the handoff take?" become reports, not guesses; you also see which source actually produces SQLs.

A shared definition: the step before the SLA

Before writing an SLA, there's something more fundamental to settle: marketing and sales meaning the same thing by "MQL" and "SQL." Most conflict comes from here — marketing counts a lead as "qualified," sales looks at the same lead and says "not ready at all"; because the definition in each one's head differs. So the two teams must sit down and agree on concrete, observable criteria: which title, which company size, which behavior makes a lead an MQL; what sales needs to verify to promote it to SQL. Without this written, shared definition, even the best lead score and the tightest SLA hang in the air. A shared definition is the invisible but most critical foundation of the handoff.

Example: the same lead, two fates

A lead visits the pricing page and downloads a guide; its score crosses the threshold and it becomes an MQL. In the first scenario there's no CRM: the lead stays in a marketing spreadsheet, sales notices three days later, and when they call, the person has moved to another solution. In the second, the CRM instantly marks the lead MQL, assigns it to sales, and per the SLA the rep calls within 30 minutes; while the lead is still warm, the conversation turns into an SQL and from there an opportunity.

The same lead, the same interest — the only difference is whether the handoff is fast and systematic. The 5-minute rule for hot leads captures exactly the value of this moment: the faster an MQL is touched as an SQL, the higher the conversion.

Common mistakes

The four most common MQL/SQL mistakes: First, setting the MQL threshold arbitrarily — a threshold based on gut, not data, floods sales with low-quality leads. Second, no SLA — without a commitment, the handoff is everyone's job, i.e. nobody's. Third, no feedback loop — if sales doesn't tell marketing why it rejected MQLs, the threshold never improves. Fourth, a slow handoff — follow-up that takes days cools even the most qualified MQL.

Summary: where to start

MQL and SQL define, in a shared language, what maturity a lead is at as it moves from marketing to sales. First clarify the MQL with a data-based lead score, write a two-way SLA between sales and marketing (how many MQLs, how fast to touch), automate the handoff in the CRM, and improve rejected MQLs with a feedback loop. Once this is built, the qualified leads marketing gathers no longer fall through the cracks; they systematically turn into opportunities and customers.