What is the difference between an SLA and a regular service contract?

A service contract sets the overall terms of an engagement — scope, price, and duration. A service level agreement (SLA) is the part that defines measurable performance standards: how fast the provider responds, how often the service is available, and what happens when those standards are missed. An SLA can be a standalone document or a schedule attached to a master services agreement. The key difference is that an SLA is built around numbers you can measure and enforce, not just a description of the work.

What is a good uptime guarantee for an SLA?

It depends on the criticality of the service. "Three nines" (99.9%) allows about 8.7 hours of downtime per year and is common for standard business software. "Four nines" (99.99%) allows roughly 52 minutes per year and is typical for critical infrastructure. Higher targets cost more to deliver, so the right number balances what the customer needs against what the provider can realistically commit to without constantly paying penalties.

What are service credits in an SLA?

Service credits are the most common remedy when a provider misses a service level. Instead of paying cash damages, the provider issues a credit against future invoices — for example, 10% of the monthly fee if uptime falls below the guaranteed level. Credits are popular because they are easy to calculate and apply automatically, but customers should check whether credits are the sole remedy or whether they can also terminate for chronic failures.

Does an SLA need to be a separate document?

No. An SLA is often included as a schedule or exhibit to a larger master services agreement (MSA) or subscription agreement rather than a standalone contract. Keeping it as a separate schedule makes it easier to update the metrics over time without renegotiating the whole contract. What matters is that the SLA is clearly incorporated into a signed agreement so its terms are legally binding.

What should be excluded from SLA measurements?

Most SLAs exclude downtime caused by scheduled maintenance (announced in advance), factors outside the provider's control (force majeure, third-party network failures, customer-side issues), and problems caused by the customer's own misuse or unauthorized changes. Clear exclusions protect the provider from being penalized for events it cannot control, but customers should make sure the exclusions are reasonable and not so broad that the guarantee becomes meaningless.

Service Level Agreement Template: How to Write an SLA

Learn how to write an SLA from scratch. Covers service levels, uptime guarantees, response times, service credits, exclusions, and what makes an SLA work.

A service level agreement (SLA) turns a vague promise — "we'll keep your service running and respond quickly" — into something measurable and enforceable. It is the part of a service relationship that says exactly how good the service has to be, how you measure it, and what happens when the provider falls short.

Whether you run a SaaS product, a managed IT shop, a marketing agency, or any business that delivers ongoing services, an SLA protects both sides: the customer knows what they're paying for, and the provider knows precisely what they're on the hook for. This guide explains what an SLA is, how to structure one, what every section should say, and the mistakes that make SLAs useless in practice.

What is a Service Level Agreement?

A service level agreement is a contract — or a schedule within a larger contract — that defines the level of service a customer can expect from a provider. It translates the relationship into numbers: uptime percentages, response times, resolution times, and the remedies that apply when the provider misses them.

SLAs are most common in technology and ongoing-service relationships:

Software and SaaS — uptime guarantees, support response times, and data backup commitments
Managed IT and MSPs — ticket response and resolution targets, on-site response windows
Hosting and infrastructure — network availability and latency guarantees
Agencies and professional services — turnaround times, revision windows, and reporting cadence

The defining feature of an SLA is that it is measurable. A regular service contract might say the provider will offer "prompt support." An SLA says: "Critical issues will receive a response within one hour, 24/7." The difference is enforceability.

SLA vs. MSA vs. Statement of Work

These three documents often appear together, and confusing them leads to gaps:

Master Services Agreement (MSA) — the umbrella contract covering the overall legal terms: liability, confidentiality, payment, termination.
Statement of Work (SOW) — defines the specific deliverables, scope, and timeline for a particular project or engagement.
Service Level Agreement (SLA) — defines the ongoing performance standards and the consequences of missing them.

In a typical arrangement, the MSA is the master contract, and the SOW and SLA are schedules attached to it. The SLA governs the quality and reliability of the service, while the SOW governs what is delivered. If you're drafting a broader services relationship, it's worth pairing your SLA with a well-structured agreement — the same discipline that goes into a strong vendor or subcontractor agreement applies here.

Key Sections of an SLA

1. Service Description

Start by describing the service the SLA covers. Be specific about scope — which systems, environments, or service tiers are included, and which are not. An SLA that covers "the platform" without defining its boundaries invites disputes about what's measured.

2. Service Level Objectives (SLOs) and Metrics

This is the heart of the SLA. Define each metric you'll measure and the target for each:

Availability / Uptime — the percentage of time the service is operational, usually measured monthly (e.g., 99.9%)
Response time — how quickly the provider acknowledges a reported issue
Resolution time — how quickly the provider fixes it
Performance — latency, throughput, or transaction speed where relevant
Support coverage — hours during which support is available (business hours vs. 24/7)

Each metric needs a precise definition. "Uptime" should specify how it's calculated and over what window. "Response time" should state when the clock starts (ticket creation) and when it stops (first human response).

3. Priority Levels

Not every issue is an emergency. Most SLAs define severity tiers so response and resolution targets scale with impact:

Critical (P1) — service is down or unusable for all users
High (P2) — major function impaired, no workaround
Medium (P3) — minor function impaired, workaround available
Low (P4) — cosmetic issues, questions, feature requests

Each tier gets its own response and resolution target. This is what prevents a provider from treating a typo report with the same urgency as a full outage — and vice versa.

4. Measurement and Reporting

Define how each metric is measured, who measures it, and how often results are reported. State the monitoring tools or methods, the reporting cadence (usually monthly), and where the customer can review performance. An SLA the customer can't independently verify is hard to enforce.

5. Remedies and Service Credits

Specify what happens when the provider misses a target. The most common remedy is a service credit — a percentage of the monthly fee credited back, scaled to the severity of the miss. For example:

Uptime 99.0%–99.9%: 10% credit
Uptime 95.0%–99.0%: 25% credit
Uptime below 95.0%: 50% credit

State clearly whether credits are the sole remedy or whether repeated failures also give the customer a right to terminate. Customers should push for a termination right after chronic breaches; providers usually want credits to be the exclusive remedy.

6. Exclusions

Define what does not count against the service levels:

Scheduled maintenance announced in advance within an agreed window
Force majeure and third-party failures outside the provider's control
Customer-caused issues — misuse, unauthorized changes, or failures in customer-side systems

Exclusions are legitimate, but watch that they aren't so broad they swallow the guarantee.

7. Responsibilities of Both Parties

A service level is only achievable if the customer holds up their end — providing access, reporting issues through the right channel, and maintaining their own systems. Spell out both parties' obligations so the provider isn't penalized for failures it couldn't prevent.

8. Review and Termination

State how often the SLA will be reviewed (annually is common), how metrics can be adjusted, and how either party can exit. Tie termination rights to the remedies section so chronic underperformance has a clear consequence.

How to Write an SLA: Step-by-Step

Step 1: Identify the parties and the service. Use full legal names and describe exactly which service the SLA covers.

Step 2: Choose your metrics. Pick the handful of measurements that actually matter to the customer — usually uptime, response time, and resolution time. Resist the urge to measure everything; a few enforceable metrics beat twenty vague ones.

Step 3: Set realistic targets. Base each target on what the provider can consistently deliver, not an aspirational number. An SLA that's breached every month erodes trust and drains revenue through credits.

Step 4: Define severity tiers. Map response and resolution targets to priority levels so urgency matches impact.

Step 5: Specify measurement and reporting. State how each metric is calculated, who tracks it, and how the customer sees the results.

Step 6: Set remedies. Decide on service credits, define the tiers, and state whether they're the sole remedy or paired with a termination right.

Step 7: List exclusions and responsibilities. Carve out events outside the provider's control and spell out what the customer must do.

Step 8: Add review, term, and signatures. Set a review cadence, incorporate the SLA into the master agreement, and have authorized signatories sign.

Common SLA Mistakes

Setting targets too high. A 99.99% uptime promise sounds impressive, but if you can only deliver 99.9%, you'll bleed service credits and goodwill. Promise what you can keep.

Vague metric definitions. "Fast response" and "high availability" are not metrics. If you can't put a number and a measurement window on it, it doesn't belong in the SLA.

No measurement method. A target with no agreed way to measure it is unenforceable. Both parties need to see the same data.

Ignoring severity levels. Treating every ticket with one response time either overcommits on minor issues or undercommits on emergencies. Tier your targets.

Burying the SLA in an unsigned document. An SLA only binds if it's incorporated into a signed agreement. A spec sheet emailed during the sales process is not a contract. The same care you'd give an independent contractor agreement applies — get it in writing and get it signed.

Forgetting customer obligations. If the customer doesn't report issues correctly or maintain their side, the provider shouldn't be penalized. Make responsibilities mutual.

SLAs for SaaS and Managed Services

Technology providers live and die by their SLAs. For SaaS, the uptime guarantee is often the single most-negotiated number in the contract, and enterprise buyers will scrutinize how it's measured. If you're building these commitments into a software or development deal, the structure overlaps heavily with a SaaS developer agreement covering service levels and support.

Managed IT and MSP relationships add on-site response windows and ticket resolution targets on top of availability. The same priority-tier discipline used in an IT consulting and MSP service agreement carries directly into the SLA: define severity, set response and resolution targets per tier, and report monthly.

When You Need an SLA

You sell software or a subscription service and customers depend on it being available
You provide managed IT, hosting, or infrastructure with uptime and support commitments
You run an agency or professional service with promised turnaround times or reporting cadence
You're a customer buying any of the above and want enforceable guarantees, not marketing promises
You're attaching performance terms to a larger services or vendor contract and need them to be measurable

Related guides

Generate Your Service Level Agreement with Contractable

A strong SLA is mostly about discipline: pick the metrics that matter, define them precisely, set realistic targets, and tie clear remedies to misses. Contractable generates customized service level agreements in seconds — with the right metrics, severity tiers, and service-credit structure for your service — so you can hand a customer an enforceable document instead of a vague promise. No lawyers or legal background required.