How much will it cost if a website receives a large influx of traffic and exceeds its data transfer allowance? If there is a catastrophic event and a website or server is inaccessible or hardware damaged beyond recovery, what compensation, if any, will the web hosting service provide? Customers are often unaware that many of answers they seek are located in the service level agreement (SLA).

A SLA is part of a legal contract for services between a service provider and a customer. A web hosting SLA formally defines what a web hosting service will be provide, when and how long the service will last, as well as remedies and exceptions to the agreement. Many of the provisions are technical specifications that allow objective measurements to ensure compliance by the web host and prevent conflicts with its customers.
In an attempt to stand out from the numerous web hosting services in the market, web hosting SLAs often include strong guarantees. The level of guaranty a web host offers may differ depending on the contracted service, but most emphasize uptime, infrastructure and hardware reliability, and customer service quality.

Uptime is the percentage of time a server or website is accessible to customers, which is a very important measurement when deciding where to host a website. Generally, hardware entails the server and its individual components, and the facility the server is housed is the facility, which includes the power, HVAC, security, and other non-hardware essentials necessary to provide web hosting. Customer service guarantees may include promised response times for questions, technical problems, or requests for additional services.

The exclusions section of an SLA is very important because it outlines when the provisions in the SLA will not apply. In these scenarios, the web hosting provider will not be liable for any damages incurred by the customers. The exclusion section usually describes the most common scenarios when downtime may occur. In order to hold a web host accountable for the times when they are supposed to be liable, you may need to have an SLA Management system in place so you know when your website is up, and when it’s down. An attentive reading of the SLA may indicate what the most common forms of downtime are with a particular web hosting service. In the event of downtime, most SLAs provide compensation to the customer in the form of service credits for future usage, which generally cannot exceed the amount paid for the service and are not redeemable for cash.