What is an SLA (Service Level Agreement)?

An SLA (Service Level Agreement) is a documented commitment about service quality — most often, in support, a promise to respond or resolve within a set time. SLAs set clear expectations for customers and clear targets for your team, and you track how reliably you meet them with an SLA attainment rate.

How SLAs work in support

A support SLA typically specifies targets like "first response within 1 hour" or "resolution within 24 hours," often varying by priority or plan tier. The agreement turns vague promises into measurable commitments — and gives your team a clock to manage against so nothing quietly slips past its deadline.

Measuring SLA attainment

You don't just set an SLA, you measure it: the SLA attainment rate is the share of interactions that met the target. Tracking attainment per priority and channel shows where you're at risk of breaching and where you need more capacity or automation to stay within commitment.

Formula

SLA attainment % = (Interactions meeting the target ÷ Total interactions) × 100

Example: If 950 of 1,000 replies hit the 1-hour first-response target, SLA attainment = 95%.

Selvo Shared Inbox

Run support from one inbox, not a free-for-all

Selvo's shared inbox turns email into real support: assignments, internal notes, saved replies, SLA tracking, and CSAT — without the duplicate replies and dropped threads a plain distribution list creates.

See how Selvo Shared Inbox works

Questions about SLA (Service Level Agreement)

What's the difference between an SLA and a KPI?

An SLA is a committed target you promise to hit (often contractually); a KPI is a metric you track to gauge performance. An SLA can be a KPI, but a KPI isn't necessarily a promise to anyone.

What happens if you breach an SLA?

Consequences depend on the agreement — for customer-facing SLAs it can mean credits or escalations; internally it flags that a commitment was missed so you can investigate and prevent repeats.

Related terms

MTTR (Mean Time to Resolution)

MTTR (Mean Time to Resolution) is the average time it takes to fully resolve a customer issue, from first report to confirmed fix. Unlike response time, it measures end-to-end resolution speed — making it a strong indicator of how effectively your team and tools close problems, not just acknowledge them.

First Response Time (FRT)

First Response Time (FRT) is the average time between a customer reaching out and getting the first human (or AI) reply. It's a first impression metric: a fast first response reassures customers their issue is being handled, even if the full resolution takes longer. It strongly influences satisfaction.

Ticketing System vs Shared Inbox

A ticketing system converts every request into a formal ticket with IDs, queues, statuses, and automation — powerful but more rigid and process-heavy. A shared inbox keeps support as natural email-style conversations the whole team can manage together. Ticketing scales structure; shared inboxes keep things personal and low-overhead.

Browse the full customer support glossary →