An SLA is a promise you make to someone else about a level of service, with a consequence attached if you miss it. A KPI is a number you track to judge how the operation is performing, with no promise and no penalty behind it. The same measurement can be both: first response time is a KPI when your support team reviews it every Monday, and an SLA when a contract says you will answer within four business hours or issue a service credit.
Last updated: August 2026.
These two get swapped in meetings constantly, usually by whoever is presenting the dashboard. It matters more than it sounds. Calling an internal target an SLA invites a customer to hold you to it, and calling a contractual commitment a KPI is how a team ends up breaching an agreement nobody told them they had signed. This is not a vocabulary argument. It decides who is owed something when the number goes red.
What is the difference between an SLA and a KPI?
The difference is obligation. An SLA is a commitment to a second party, written down, with a defined threshold and a stated consequence for missing it. A KPI is an internal measure of performance with no counterparty and no penalty. SLAs create accountability pointing outward, to a customer or another department. KPIs create accountability pointing inward, to management.
Everything else follows from that. Because an SLA has a consequence, its definition has to survive an argument: what exactly starts the clock, what pauses it, which tickets are excluded, and what happens on a holiday. A KPI never has to survive that argument, so most KPI definitions are loose, and that looseness is fine right up until someone promotes the KPI into a contract without tightening it.
A KPI can also measure things an SLA never could. You can commit to answering in four hours because answering is entirely within your control. You cannot commit to a customer satisfaction score, because that number is somebody else's opinion. Any metric that depends on how a customer feels belongs in the KPI column permanently.
SLA vs KPI: side by side
| SLA | KPI | |
|---|---|---|
| What it is | A written commitment to a level of service | A number used to judge performance |
| Who it is for | A customer, a vendor, or another internal team | The team and its management |
| Where it lives | A contract, an order form, or a published support policy | A dashboard, a scorecard, a QBR deck |
| Threshold | Fixed and negotiated. Changing it needs the other party | Set internally. Can be raised next quarter by decision |
| If you miss it | A defined remedy: service credit, escalation right, termination clause | A conversation, a root cause, a plan |
| How it is measured | Per event, usually against a percentile of all covered events | Usually an average or a rate across a period |
| Time horizon | Per ticket, measured over a contractual window such as a month | Trended over weeks, quarters, years |
| Typical owner | Legal plus the service owner | The operations or support manager |
| Can it cover opinion? | No. Only things you fully control | Yes. CSAT, NPS, and effort scores are all KPIs |
What is an SLA?
A service level agreement is the section of a contract that states what level of service the provider will deliver and what the customer gets if the provider falls short. It is a legal instrument with a measurement attached, not a measurement with legal language attached, and the difference shows up in how carefully each part is written.
A usable SLA has six parts. The service description says what is covered, because "support" is not a scope. The metric names one thing that can be counted. The target gives the threshold and, critically, the percentage of events that must meet it. The measurement window says over what period compliance is judged and which clock is running, business hours or calendar hours. The exclusions list what does not count: customer-caused delays, scheduled maintenance, force majeure. The remedy states the consequence, which in most software contracts is a service credit calculated as a percentage of the monthly fee.
Miss any one of those and you have a sentence rather than an agreement. The most commonly missing part is the percentage. "We will respond within four hours" reads like a promise about every ticket, and a customer will argue it that way. "We will respond within four business hours to 95 percent of priority-two tickets in a calendar month" is a commitment you can actually operate against. For the full anatomy of these documents and where they sit inside a broader agreement, see how a service level agreement differs from a contract, an MSA, and an SOW.
SLAs also point inward. An agreement between two internal teams, say between support and engineering on how fast a bug escalation gets picked up, is usually called an OLA, an operational level agreement. It behaves exactly like an SLA except the remedy is organizational rather than financial. Most customer-facing SLAs quietly depend on an OLA nobody wrote down, which is why support teams so often breach commitments over work that was never theirs to do.
What is a KPI?
A key performance indicator is a metric chosen because movement in it tells you something real about whether the operation is getting better or worse. The load-bearing word is "key". A support operation can count four hundred things. A handful of them change behavior when they move, and those are the KPIs; the rest are metrics you keep in a report and look at when something breaks.
The useful split inside KPIs is leading versus lagging. Lagging KPIs tell you what already happened: churn rate, resolution time last month, CSAT for the quarter. Leading KPIs move first and predict the lagging ones: ticket backlog age, the share of tickets reopened, how long a queue sits unassigned. A dashboard made entirely of lagging KPIs is a history lesson. You want enough leading indicators that you find out about a problem before the customer tells you. Our full list of customer service metrics and KPIs worth tracking covers which ones actually earn a place on the board.
KPIs also carry no contractual weight, which is their advantage. You can change the definition, raise the target mid-quarter, or drop the metric entirely once it stops teaching you anything. Try that with an SLA and you are renegotiating with a customer.
SLA and KPI examples for a support operation
Most support measurements can play either role. What changes is the definition, not the name.
| Measurement | As a KPI | As an SLA |
|---|---|---|
| First response time | Median FRT across all tickets, trended weekly | 90 percent of P2 tickets answered within 4 business hours |
| Resolution time | Average resolution time by queue and by agent | P1 incidents resolved or worked around within 24 hours |
| Uptime | Monthly availability of each service, trended | 99.9 percent monthly availability or a 10 percent credit |
| Escalation response | Share of escalations picked up inside an hour | An OLA: engineering acknowledges a P1 page in 15 minutes |
| Ticket backlog | Open tickets older than 7 days | Rarely used. Backlog depends on inbound volume |
| First contact resolution | FCR rate by channel | Never. You cannot promise a question is simple |
| CSAT | Rolling 30-day satisfaction score | Never. It measures the customer's opinion, not your work |
The bottom three rows are the ones teams get wrong. A vendor that agrees to a CSAT floor in a contract has agreed to be penalized for something a customer controls, and a customer that asks for one is asking for a number the vendor will start managing by suppressing surveys. If you want the underlying formulas and benchmarks for these, the pages on first response time and average resolution time have them.
Can a KPI be an SLA?
Yes, but not by relabeling it. A KPI becomes an SLA when three things get added: a percentile rather than an average, an explicit clock definition with exclusions, and a remedy. Until all three exist you have an aspiration with a number next to it. Promoting a KPI to an SLA is a rewrite, not a copy and paste.
The reverse is common and harmless. Every SLA should have a matching KPI that the team watches internally, usually set tighter than the contractual threshold so there is warning before a breach. If you promise four hours, run the internal target at two and a half.
Which comes first, the SLA or the KPI?
The KPI, always. You need several months of real distribution data before you can commit to a threshold, because an SLA is a promise about the tail of your performance and a KPI usually reports the middle of it. Signing an SLA you have never measured is how a team discovers its four-hour promise is a nine-hour reality.
In practice: instrument the metric, watch it for a quarter, look at the 90th and 95th percentiles rather than the average, set the contractual threshold above the 95th, then negotiate. Teams that skip the measurement step and copy a competitor's published SLA are inheriting someone else's operational capacity.
Where teams get SLA vs KPI wrong
They publish a KPI as if it were a promise. A help center page saying "we typically reply within one hour" is a KPI written in public. Customers read it as a commitment, and in a dispute it is evidence. If a number is going on a public page, either add the qualifying language that makes it a description of typical performance, or accept that you have created an SLA without a remedy clause and without exclusions, which is the worst version of both.
They set the SLA at the average. This is the single most expensive mistake here and it is almost universal. If your average first response time is three hours, roughly half your tickets take longer than three hours, so a three-hour SLA breaches on close to half of them. An SLA threshold has to come from a percentile. Take the 95th percentile of the last quarter, add margin, and commit to that. The gap between a median and a 95th percentile in a real support queue is usually a factor of three or more, which is why teams that set thresholds off their dashboard average start breaching immediately and cannot explain why.
They never define the clock. Does the timer pause when you are waiting on the customer? Does it run overnight, over a weekend, on Thanksgiving? Is a reopened ticket a new event or the same one? Unanswered, each of these becomes a dispute at renewal, and the customer's reading always wins because they did not write the ambiguity. Our breakdown of response time versus resolution time in an SLA covers where these clocks usually diverge.
They measure the SLA somewhere other than the KPI. Support reports FRT from the help desk, the customer measures it from their own ticket log, and the two disagree by an hour because of how the systems handle auto-replies. Agree on the system of record inside the agreement itself. The same discipline applies to availability commitments, where the provider's internal graphs and an independent uptime monitoring check running from outside the network routinely disagree about whether a service was actually reachable, and the customer's version is the one that ends up in the credit request.
They let SLAs multiply. Every enterprise deal adds a slightly different threshold until the support team is operating against eleven variants nobody can hold in their head. Standardize on two or three tiers and treat anything else as an exception requiring approval. The escalation matrix is where those tiers become operational.
Frequently asked questions about SLA vs KPI
Is an SLA a KPI? No. An SLA is an agreement that contains one or more metrics with committed thresholds and a penalty for missing them. A KPI is a metric used internally to judge performance, with no counterparty and no penalty. The same underlying measurement, such as response time, can appear in both, defined differently in each.
What is an example of an SLA and a KPI for the same metric? Uptime is the cleanest example. The KPI is monthly availability tracked on a dashboard and trended over the year. The SLA is the contractual line that says availability will be at least 99.9 percent in a calendar month, excluding scheduled maintenance, with a service credit of 10 percent of the monthly fee if it is not met.
Can you have an SLA without a KPI? Technically yes, and it is a bad idea. Without an internal KPI tracking the same measurement continuously, the first time you learn about a breach is when the customer requests a credit. Every SLA should have a corresponding internal KPI with a tighter threshold so the team gets warning.
What is the difference between an SLA, an OLA, and a KPI? An SLA commits a provider to a customer. An OLA, an operational level agreement, commits one internal team to another and exists to make the SLA achievable. A KPI measures performance for management with no commitment attached to either party.
What is the difference between an SLA and an SLO? An SLO is the internal objective you engineer toward, and the SLA is the external promise built on top of it, usually looser. The SLO is where error budgets live. We cover the full relationship, including SLIs, in SLA vs SLO vs SLI.
Should CSAT be in an SLA? No. CSAT measures a customer's opinion, which the provider does not control and the customer is not obliged to supply honestly or at all. Putting a satisfaction floor in a contract creates an incentive to manage the survey rather than the service. Keep CSAT as a KPI and reserve the SLA for things you can execute.
Who owns SLAs and KPIs? The service owner drafts both, legal approves the SLA language and the remedy, and the operations manager runs the KPI review. When nobody owns the SLA operationally it becomes a document that only reappears during a dispute, which is the failure mode behind most credit requests.
Both of these live or die on the same thing, which is whether the back-office work behind the number is actually running. The threshold in the contract is downstream of queue design, staffing, and routing, all of it customer experience operations rather than customer-facing polish. For the SLA documents themselves, with real thresholds and structures you can copy, see our customer service SLA examples and metrics.