A perquisite, often shortened to perk, is an extra benefit that comes with a job beyond your salary, such as a company car. A prerequisite is something that must be completed or in place before something else can happen, such as a qualifying exam. Remember: pre-requisite starts with pre-, meaning it comes before; a perquisite is what you get once you already have the job.
The core difference
A perquisite is a bonus benefit, while a prerequisite is a requirement that must come first.
- Perquisite — a monetary or other incidental benefit beyond salary: a company car was one of the perquisites of the role.
- Prerequisite — something that must be in place or completed before something else can happen: basic algebra is a prerequisite for the calculus course.
How to tell them apart
The words look alike because they share the same base, but their prefixes point in opposite directions. Prerequisite begins with pre-, meaning before, which matches its meaning of something required beforehand, like a qualification you need before you can enrol on a course. Perquisite has no such prefix; it comes from a Medieval Latin word meaning something acquired for profit, which is why it settled into the modern sense of a job perk.
The confusion usually shows up in workplace writing, where someone means to describe a benefit, such as private healthcare or a gym membership, but reaches for prerequisite by mistake. If the word describes something you receive, it is a perquisite; if it describes something you must complete first, it is a prerequisite.
