What a 99.9% Uptime SLA Really Covers
Three nines sounds absolute, but the detail is in the definitions. What 99.9% means in minutes, how it is measured, and what service credits do and do not cover.
Support Team
Customer onboarding and setup guides
2 min read
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Key takeaways
- 99.9% availability allows roughly 43 minutes of downtime in a 30-day month, or about 8.8 hours across a year.
- How and where availability is measured matters as much as the headline percentage.
- Service credits compensate for a breach; they are not insurance against lost revenue, so architecture still matters.
At a Glance: Editor's Verdict
Tested on Virgin Media, BT Smart Hub & Sky Broadband (Updated October 2026)
The Pros
- ✓Dedicated 10Gbps London edge routing bypasses ISP throttling during matchdays
- ✓Native 50/60fps UK broadcast frame rate eliminates motion judder on OLED/QLED
- ✓Full 3pm Saturday Premier League coverage via international English broadcast feeds
- ✓Direct human UK support available 7 days a week on WhatsApp (< 2 min reply)
- ✓3-day money-back guarantee with zero long-term contract lock-in
The Cons
- ✕High-bitrate 4K UHD streams require at least 25 Mbps stable broadband
- ✕Base subscription includes 1 connection (multi-room requires multi-screen package)
- ✕24h trial requires £1 nominal fee to prevent bot and freeloader lag
- ✕Virgin Media & BT users must disable default parental filters (Web Safe / Web Protect)
The numbers behind the nines
An uptime percentage is a budget for downtime. At 99.9%, a service can be unavailable for about 43 minutes in a 30-day month. At 99.95% that falls to around 22 minutes, and at 99.99% to just over four minutes. Each extra nine is a large step in engineering effort, which is why contractual commitments are usually more conservative than measured performance.
The period matters too. A monthly SLA resets every month, so a bad month cannot be offset by good ones, while an annual figure can hide a long outage inside a strong year. Check which window applies and whether planned maintenance, announced in advance, counts towards the budget or is excluded.
How availability is measured
Two providers can both promise 99.9% and mean different things. Some measure from their own infrastructure, others from external monitoring locations, and others from the error rate of real requests. A definition based on the share of successful requests usually reflects viewer experience better than a simple check that a server answers.
Look closely at what counts as downtime. Is a severely degraded service treated as unavailable, or only one that returns errors? Are regional problems included, or does the whole platform need to fail? Clear definitions protect both sides and make it possible to verify a claim against your own monitoring data.
Credits, exclusions and what they mean for you
When an SLA is missed, the usual remedy is a service credit: a percentage of the monthly fee applied to a future invoice, often tiered by how far availability fell. Most agreements require you to claim within a set period and exclude issues caused by your own origin, your configuration or events outside the provider's control.
Credits recognise a breach, but they rarely match the cost of a failed live event. That is why the architecture behind an SLA matters more than the percentage on the page. Redundant routing, multiple CDNs and protected origins reduce the chance of an outage in the first place, which is worth far more than compensation afterwards.
Questions about your own setup?
Message our London team on WhatsApp, 24 hours a day, 7 days a week (UK Team).