Define: High Severity

What High Severity Means in a Contract

High Severity is a defined term used in agreements, particularly those governing information technology, data handling, and security, to classify the most serious category of incident that a party can experience or cause. When a contract labels an event as High Severity, it usually means the incident has caused, or is likely to cause, substantial disruption to systems that are essential to running the business, or has resulted in unauthorized external access to sensitive information.

The purpose of the classification is practical rather than decorative. Parties negotiate tiered severity levels, often Low, Medium, High, and sometimes Critical, so that both sides know exactly what response is expected without having to argue about the seriousness of an incident after it has already happened. High Severity sits near the top of that scale, just below or alongside Critical, and it is the trigger point at which contractual obligations become most demanding.

Because the consequences of misclassifying an incident can be significant, from missed notification deadlines to reputational damage, contracts increasingly spell out High Severity with specific, measurable criteria rather than leaving it to subjective judgment.

How High Severity Is Defined or Measured

Most agreements define High Severity by reference to two overlapping factors: the scope of the information involved and the operational impact on systems. A typical clause will describe High Severity as external loss or exposure of protected information causing significant impact to mission-critical information technology systems, including large-scale outages. Each element of that phrase does work:.