Because Tinder identified what it considers a violation of its Community Guidelines or its Terms of Use. When that happens you receive an email, and you see a notification when you try to log in. If you believe the ban was an error, you can appeal it from Tinder's Appeal Center.

How Tinder tells you

Tinder does not leave you guessing about whether it happened. A banned account gets an email, and a notice appears when you try to log in. Keep that email. It is from Tinder, it is about your account, and it is the starting point for anything you do next.

Then go to the Appeal Center and sign in with your usual Tinder login. The violations on your account are listed there, because that is where you choose which ones to appeal. The one you find is the most direct answer to the question in the title.

Reports from your matches

Coaching material on app bans puts user reports near the top of the list of causes. The behavior it names is racist, sexist or insulting treatment of a woman who then reports it. That covers more than most men think.

A sour reply after she stops answering counts. So does a crude line she never invited, a comment about her body meant as a joke, or pushing for a meetup after she has said no. From her side of the screen, each of those is a stranger being unpleasant, and the report button is right there.

Dates count too. One coach who has been on plenty of first dates from the apps has a habit worth copying. Even when a date is disappointing, he stays polite for ten or fifteen minutes before he leaves. Part of the reason, he says, is that he does not want to be reported on the app. Walking out rudely is a fast way to earn a report from a woman you never messaged again.

What in your messages gets flagged

Tinder's guidelines say it will not tolerate violent content, and that includes descriptions of violent acts, not only images. A dark joke about hurting someone can read as exactly that to a moderator who does not know you.

The same coaching material lists using the apps for something besides dating. Promoting a business, a podcast or an Instagram account through your chats counts. If your opener is a link, you are not using the app the way it is meant to be used.

A simple test covers most of it. If you would not say it across a table on a first date, it does not belong in a message.

What your photos can break

Tinder's guidelines tell you to post your own content, and not to post images of other people without their consent or work that someone else owns. They also ban fake accounts and pretending to be someone you are not, even as a joke.

So a set that includes a model's photo, a celebrity, or a better-looking friend passed off as you is a clear violation. So is violent imagery, including the use of weapons. If any photo in your set fits those descriptions, you probably have your answer.

Swiping habits that look like a bot

Coaching material on bans also names auto-swiping tools, because apps treat that activity as bot behavior. If you ever used an app or a script to like on autopilot, that is a likely cause.

The same list includes making a new account after an earlier ban. Tinder is explicit that a banned account cannot create new ones, so a second account is a violation in its own right.

Ban or suspension

Read the notice carefully, because Tinder suspends accounts as well as banning them. Its Appeal Center glossary defines a ban as removing your profile and stopping you from accessing the account or creating new ones. A suspension restricts access for a period, and the account comes back automatically when it ends, unless there are more violations.

If your notice says suspended, the situation is very different. Wait it out and keep your nose clean.

The one route back

If you believe the ban was an error, appeal it. Sign in to the Appeal Center with the same login details as your Tinder account, find the violation, select it, tap Begin appeal, then tap Submit appeal. Select every violation you want contested before you submit.

Do not open a new account while you wait. And whatever happens with the appeal, reread your last few conversations as if a stranger wrote them. A ban that changes nothing about how you talk to women is usually followed by another one.