If you have built a website in the last decade, there is a good chance someone -- a designer, a theme developer, your own taste -- removed the underlines from your hyperlinks. The browser default is blue text with an underline, and almost every modern site has decided that the underline is ugly. The underline got swapped for a colour change, or a hover effect, or nothing at all. That choice is the single most common WCAG 2.1 failure we see in small-business audits. It is not the worst failure, and it is not the most expensive to fix. But it is everywhere, it is invisible to the people who made the decision, and on the wrong day it can be exactly the kind of thing that ends up in an ADA demand letter or an EAA enforcement notice. This article explains why a missing underline matters, what the law actually requires, and how to keep most of the visual cleanliness your designer wanted while still passing accessibility checks. No developer skills required to follow along.…