Prediction Market Terms of Service: What to Check Before You Sign Up

TL;DR

• Kalshi requires binding individual arbitration with a 30-day window to opt out; Limitless arbitrates in Panama and Predict.Fun in the British Virgin Islands, and neither describes an opt-out option.
• A cancelled or postponed event does not mean an automatic refund. Kalshi can reschedule a contract's timing or settle it at the last traded price; Limitless is the only one of the five platforms with a documented refund-at-cost policy.
• Polymarket's international platform blocks US trading outright. Its separate, CFTC-regulated Polymarket US arm is a different legal entity with its own rulebook and dispute process.
• Every platform reserves broad discretion to suspend or freeze an account, but what actually gets frozen differs: a bank-linked account on Kalshi or Polymarket US versus interface access on the on-chain platforms, where funds sit in a self-custodied wallet, not a company account.

Signing up for a prediction market account and skimming past the terms of service to get to the trading screen faster? Most of that document is boilerplate. Five clauses inside it are not: what it takes to get your money out, when the platform can freeze your account, how a dispute actually gets resolved, which countries are locked out, and what happens to your contract if the underlying event gets rescheduled or cancelled. Here's what Kalshi, Polymarket, Limitless, Predict.Fun, and Opinion's own terms actually say about each one.

Why Does a Prediction Market's Terms of Service Matter So Much?

A brokerage account and a prediction market account are not the same instrument. A broker holds your shares and owes you fiduciary duties under securities law. A prediction market platform is a counterparty to a contract.

Its terms of service is the only document that says what happens when a market gets contested, a government agency delays the data a contract depends on, or your account gets flagged for review. That document is also where regulatory status does most of its practical work. It decides who can trade, how disputes get resolved, and whether a "frozen account" means a blocked login screen or a blocked bank transfer.

Read the terms once, at signup, before you have a position open. Reading them after a dispute starts is reading them too late.

What Withdrawal Conditions Should You Check Before You Deposit?

Three questions to answer before you fund an account: what identity verification triggers a withdrawal hold and how long it lasts, whether the platform pays out in fiat or only in crypto, and whether there's a minimum holding period before funds tied to a resolved contract can move.

Kalshi is a CFTC-regulated exchange. It settles in US dollars through standard bank transfer rails, which puts ordinary bank processing time into the picture rather than blockchain confirmation time.

Polymarket, Limitless, and Predict.Fun settle on-chain instead. Withdrawal speed there depends on network conditions, not a bank's processing window, and all three run on a different custody model than Kalshi, one where funds sit in a user's own wallet rather than a company account. That distinction matters for what a "freeze" can actually touch: these platforms can block your access to their own front end, but they can't reach into a self-custodied wallet the way a bank can put a hold on an account.

Predict.Fun's terms make this concrete. They allow the company to place a wallet in "close-only mode," letting existing positions close out without permitting new ones, specifically in response to VPN use or other attempts to get around its KYC requirements and jurisdiction checks. That's a narrower, more specific power than a blanket account freeze, and it's spelled out in the terms rather than left to unexplained discretion.

Opinion's withdrawal terms weren't publicly accessible for this review. Treat that as a reason to check the current terms directly before funding an account, not as evidence either way.

Under What Conditions Can a Prediction Market Freeze Your Account?

Every platform reserves broad discretion to suspend or freeze an account. None of the five promise they won't. What differs is how that discretion is written down, and what it actually reaches.

Kalshi's Member Agreement gives the exchange the right to grant, deny, condition, suspend, or revoke a member's access, and failure to comply with the agreement can lead to suspension or termination at Kalshi's discretion. Because Kalshi is a bank-linked, brokerage-style account, a freeze there can mean funds genuinely held, not just a blocked login.

Limitless's terms spell out specific triggers: suspected fraudulent, manipulative, or illegal activity, a change in regulatory requirements, technical or security concerns, suspicious behavior, non-compliance with eligibility rules, or an incomplete identity check. That's a more detailed list than most platforms publish.

Predict.Fun goes broader in one direction and narrower in another. Its terms allow the company to suspend or disable its services, in whole or in part, temporarily or permanently, for any reason whatsoever, about as broad as a discretion clause gets. But they also carve out the close-only-mode mechanism described above for jurisdiction and VPN issues specifically, rather than leaving every enforcement action undefined.

Polymarket's structure splits by product. The international platform is non-custodial, so there's no company-held balance to freeze. What Polymarket can restrict there is your access to its own interface, not funds already in your wallet. Polymarket US, the platform's separate CFTC-regulated arm, instead follows the same exchange-style model as Kalshi: it can limit, condition, restrict, suspend, or terminate trading and clearing privileges under its own rulebook.

Opinion's account-freeze terms weren't publicly documented at the time of this review.

How Are Disputes Resolved on a Prediction Market Platform?

This is the clause people skip and then regret, and it's also where the five platforms diverge the most.

Kalshi requires binding arbitration on an individual basis only. Its terms explicitly bar class, collective, or representative proceedings, and new members get a 30-day window after accepting the agreement to opt out, by emailing support with "Arbitration Opt-Out" in the subject line. Miss that window and arbitration becomes mandatory.

Limitless's terms route disputes to binding arbitration administered under the International Chamber of Commerce's Rules of Arbitration, seated in Panama City, Panama, applying Panamanian law, before a single arbitrator. Each side bears its own costs. There's no opt-out mechanism described in the terms.

Predict.Fun requires a 90-day good-faith negotiation window first: a written notice, a 20-day response period, and a meet-and-confer process. Only after that fails does the dispute move to binding arbitration before the BVI International Arbitration Centre, in English, seated in the British Virgin Islands under BVI law. Jury trials and class actions are both waived.

Polymarket US routes disputes through its own Rulebook and Clearing Rulebook, the same kind of regulator-reviewable process a traditional exchange would use. The international platform's terms include a dispute-resolution section, but its specific arbitration venue and opt-out terms weren't confirmed from a primary source for this review. Don't assume it mirrors Polymarket US, or any other platform's process, without checking the current terms yourself.

Opinion's dispute-resolution terms weren't publicly documented at the time of this review, beyond the fact that individual market outcomes are determined by "Opinion AI" against a named data source, which is a market-resolution mechanism, not an account-level dispute process.

Which Geographic Restrictions Apply to Prediction Markets?

Kalshi's CFTC regulation gives it a federal framework that preempts most state-level restrictions, which is why it can offer retail access across the US without a patchwork of state rules.

Polymarket's international platform blocks trading in the United States outright, along with OFAC-sanctioned jurisdictions: Cuba, Iran, North Korea, Syria, and Russia, plus Crimea, Donetsk, and Luhansk. Polymarket US exists specifically to serve the market the international platform locks out, under its own CFTC registration.

Limitless blocks access entirely, not just trading, for Russia, Belarus, Cuba, Iran, North Korea, Syria, and those same three sanctioned regions. It blocks trading specifically for users in the United States, China, Ontario, and Alberta, and requires users to be at least 18 and off OFAC, EU, and UK sanctions lists.

Predict.Fun's restricted-trading list is the longest of the five: the United States, United Kingdom, France, Ontario, Singapore, Poland, Thailand, Taiwan, Australia, and Belgium, on top of the standard sanctioned-country list.

Opinion's geographic restrictions weren't publicly documented in a form this review could confirm. Treat its access as jurisdiction-dependent and check the current terms before funding an account from outside a major market.

None of this is static. A platform's restricted list can change after a regulatory action in a specific jurisdiction, and the terms get updated to reflect it, often without a prominent announcement. Check the terms at signup, and check them again before you scale up a position, especially if you travel or hold dual residency.

What Happens to a Contract When a Platform Invokes Force Majeure?

This is the clause nobody reads until a market gets cancelled out from under them, and it's also where a simple "void and refund" assumption breaks down fastest once you check each platform's actual rules.

Kalshi does not refund at cost for a routine postponement. Its DCM Rulebook first lets Kalshi adjust a contract's expiration date and timing if the event is rescheduled in a way that would prevent an accurate result, a grace-period extension, not a resolution. If the outcome still can't be determined after that, Kalshi settles using the contract's last traded price if one is fair, or failing that, a binding "fair allocation" determination by its Outcome Review Committee that isn't subject to further review. A genuine refund mechanism does exist, but it sits under Kalshi's emergency powers, natural disasters, system failures, extraordinary market threats, not the routine handling of a postponed game.

Polymarket's 50/50 fallback is real but far from the typical outcome. Most postponement or non-occurrence scenarios are already covered by a market's own written edge-case rules and resolve normally through an unopposed or once-disputed proposal. The 50/50 split, where each side redeems for $0.50, only shows up after a proposal is disputed, a second proposal is made, and that's disputed again, escalating to a vote by UMA token holders. Polymarket's own documentation calls this outcome rare. A "market clarification" can refund the original trade cost, but only for trades placed before the clarification was announced, not after.

Limitless is the one platform with an actual refund-at-cost policy for a cancelled event, and it's conditional. A "misresolved" market, one where the published criteria are ambiguous or can't be applied to the real-world result, refunds the original amount wagered. But if that specific market's own rules already define an outcome for the scenario (their docs cite a cancelled game as an example), those rules control instead. The refund fallback only applies when the market's own rules are silent.

Predict.Fun's force majeure clause names specific triggers: equipment malfunctions, scheduled maintenance, causes beyond the company's control, blockchain infrastructure disruption, and third-party service failures. But its terms also describe transactions as irreversible and final, with no refunds, so a force-majeure-triggered outage doesn't appear to guarantee a refund path the way the clause's name might suggest. Read the two sections together, not separately.

Opinion's cancellation and force majeure terms weren't publicly documented for this review. Its markets resolve against a named data source, so a delayed or revised data release is the most likely trigger for a dispute, but how that resolves at the terms-of-service level isn't confirmed.

This table compares documented mechanics, not live pricing, because the underlying rules are what still holds true next year.

What Should You Check Before You Sign Up?

• Withdrawal method matches what you can actually use: bank transfer or crypto wallet.
• Identity verification requirements and timing are clear before you deposit.
• Conditions for an account freeze are listed, not just left to unexplained discretion, and you know whether a freeze blocks your login or your funds.
• Dispute path is arbitration, and you know the venue, the governing law, and whether there's an opt-out window.
• Geographic restrictions apply to your location, now and if you travel.
• Force majeure and cancellation outcomes are platform-specific, not a uniform "void or refund," so check the actual rule for the platform and market category you trade.
• Resolution criteria for the specific market category you trade are named and verifiable.

How Do the Five Platforms' Terms of Service Compare Structurally?

None of this replaces reading a platform's actual terms before you fund an account, but it's the shortlist of clauses worth reading closely instead of scrolling past. For how Kalshi and Polymarket compare beyond legal structure, on fees, liquidity, and custody, see our Kalshi vs. Polymarket comparison. Before you commit capital to any one platform's terms, it's worth comparing live odds on the same event across all five on our cross-platform dashboard.

Sources

• Kalshi. "Kalshi Member Agreement." kalshi-public-docs.s3.amazonaws.com
• Kalshi. "DCM Rulebook." kalshi.com/regulatory/rulebook
• Polymarket. "Terms of Use." polymarket.com/tos
• Polymarket. "How Are Markets Disputed?" help.polymarket.com
• Polymarket US / CFTC filing. "Polymarket US Rulebook," November 25, 2025. cftc.gov
• Limitless Exchange. "Terms of Service." docs.limitless.exchange
• Predict.Fun. "Terms of Service." docs.predict.fun

PredictionHero aggregates publicly available prediction market data for informational purposes only. This is not financial or legal advice. Prediction markets may not be available in all jurisdictions.