You must be 18 or older to open a Kalshi account. That applies in every state Kalshi operates in, including states where sports betting requires you to be 21, because Kalshi is regulated as a federal exchange rather than a state gambling operator. Kalshi verifies identity at sign-up, with a Social Security number for US users and an ID document if it asks.
The rule
Kalshi's sign-up page states it plainly: users must be 18 years or older. There is no state-by-state variation on Kalshi's side. You also have to pass identity verification, which uses the personal details you enter and, where Kalshi requests it, a government ID.
Why 18 and not 21
Sportsbooks are licensed by state gaming regulators, and most states set the betting age at 21. Kalshi is a Designated Contract Market registered with the CFTC, the federal derivatives regulator, which sets no minimum age beyond the legal age to enter a contract. Kalshi applies 18, the same age you need to open a brokerage account.
This is more than trivia. The age gap is one of the things state attorneys general point to when they argue Kalshi's sports contracts are sports betting without the safeguards states require. Whether that argument wins is being decided court by court; see Is Kalshi gambling? and our state pages.
How it compares
| Platform | Minimum age | Why |
|---|---|---|
| Kalshi | 18 | Federal exchange; no state age rule applies |
| Polymarket | 18 | Platform rule |
| Novig | 21 | Voluntary; Novig says it's the only prediction market to require 21 |
| Robinhood prediction markets | 18 (runs on Kalshi) | Brokerage account age |
| DraftKings / FanDuel sportsbooks | 21 in most states | State gaming law |
What happens if you lie about your age
Verification will usually catch it, and if it doesn't, any winnings sit in an account you can't legally hold. Kalshi can close the account and is required to keep records for the regulator. Not worth it.
Responsible trading tools
Kalshi has a Responsible Trading Hub with deposit limits, time-outs and self-exclusion. If you're 18 and new to this, setting a deposit limit on day one is the single most useful thing you can do. And if trading stops being fun: 1-800-GAMBLER.