Polymarket vs Kalshi: What Differs for Traders Outside the US

Polymarket and Kalshi look like rivals on price, but their taker fees follow the same formula, and both pay a fixed amount per winning contract: $1 on Kalshi, 1 pUSD on Polymarket. The choice is mostly not about cost. It is about who regulates the venue, who holds your money, what you get paid in and whether your country is allowed.

Quick answer

Polymarket’s international platform is an onchain market on Polygon. You keep your own funds, settle in pUSD (a token backed by USDC) and sign up with an email code or a crypto wallet. Its site disclaimer says it is not regulated by the CFTC. Kalshi is a CFTC-regulated exchange: funds sit in a member account, contracts are priced and paid in dollars, and you verify your identity and country at sign-up. Both restrict a list of countries, and the lists differ.

Side by side

	Polymarket (international)	Kalshi
Regulation	Not regulated by the CFTC	CFTC Designated Contract Market
Who holds funds	You, in your wallet	Your member account
Paid in	pUSD, backed by USDC	US dollars
Sign-up	Email code or wallet	Identity and country check
Taker fee	Rate × p × (1 − p)	Rate × p × (1 − p), rounded up
Maker fee	None	Only where a market lists one
Outcome set by	UMA Optimistic Oracle	Kalshi, from the source in the rules

Which Polymarket are you using?

Polymarket runs two platforms. Its disclaimer says Polymarket US “is operated by QCX LLC d/b/a Polymarket US, a CFTC-regulated Designated Contract Market,” and that the international platform “is not regulated by the CFTC and operates independently.” Outside the US you use the international one, and this guide means that platform. Kalshi is a Designated Contract Market, a US designation for exchanges that list futures, swaps and options.

Who holds your money?

On Polymarket, assets are held in your wallet, secured by your private key, and trades settle through smart contracts. Polymarket “never takes possession of your funds.”

On Kalshi, you fund a member account. The Member Agreement lets Kalshi clear through a CFTC-registered derivatives clearing organization, and says cash held there on your behalf may be invested by Kalshi as CFTC rules allow. You hold an account at a regulated exchange, not a wallet you control.

On Polymarket the keys are your job. On Kalshi your access depends on the account and its terms.

What do you settle in?

Polymarket uses pUSD, “a standard ERC-20 token on Polygon, backed by USDC.” One pUSD creates one Yes and one No share, and a winning share redeems for 1 pUSD. Polymarket says it charges no fees to deposit or withdraw USDC, though third parties such as on-ramps may.

On Kalshi, price is “the price of a contract in dollars,” and winning contracts “are paid out to your cash balance.” Outside the US, deposit and withdrawal methods depend on your region. Check them and their fees before you fund.

How do the fees work?

Both charge takers rate × contracts × p × (1 − p), where p is the price between 0 and 1. The term p × (1 − p) peaks at 50 cents (0.25) and shrinks toward 0 and $1. Polymarket sets the rate by market category, and some categories are fee-free. Kalshi has a general rate, some markets carry their own, and the fee is rounded up.

With an example rate of 0.07, 100 contracts cost:

Price	Stake	Fee	Fee as share of stake
10 cents	$10	$0.63	6.3%
50 cents	$50	$1.75	3.5%
90 cents	$90	$0.63	0.7%

In dollars the fee peaks at 50 cents. As a share of your stake it is rate × (1 − p), so it is highest on cheap long shots.

Makers pay nothing on Polymarket. On Kalshi they pay only where a market lists a maker fee, charged when the resting order fills. More in maker vs taker fees.

What fee do you need to beat?

Add the fee per contract to the price to get your break-even. At 50 cents and the example rate, the fee is 1.75 cents a contract, so a Yes only pays if the true chance is above 51.75%. At 10 cents the fee is 0.63 cents, so you need more than 10.63%. Run this with the current rate for the market you trade.

Where can you trade?

Neither platform is open everywhere, and the lists do not match.

Polymarket sorts countries into three groups in its geoblock docs: blocked completely, close-only on the site and API (you can close positions but not open new ones), and close-only on the website only.
Kalshi lists Restricted Jurisdictions in its Member Agreement. The list has changed several times in a year.

Read the current list for your country on each platform before you deposit.

Who decides the outcome?

Polymarket event markets resolve through the UMA Optimistic Oracle: a bonded proposal, a 2-hour challenge window, and a token holder vote if disputed twice. On Kalshi, the markets team sets the outcome from the source named in the market’s rules, which Kalshi says takes “anywhere from one hour to more than twelve hours” after close. More in how prediction markets are resolved.

What this means for a trader

Check access first. Close-only lets you exit, not enter.
Pick custody on purpose. A wallet you control, or an account at a regulated exchange.
Price the fee into the trade. As a share of stake it costs most on long shots.
Read the market’s rules. The resolution source decides what you get paid.

Current rates, regions and sources are on Polymarket and Kalshi.

Frequently asked

Is Polymarket regulated? Its disclaimer says the international platform is not regulated by the CFTC. Polymarket US is a separate, CFTC-regulated exchange.

Can I use Kalshi outside the US? Kalshi says you can trade from many countries, subject to its Member Agreement, which lists restricted jurisdictions.

Do I need KYC? Kalshi asks you to verify your identity and country. Polymarket’s sign-up steps describe an email code or a wallet connection.

Which is cheaper? At the same rate, neither. Polymarket’s rate varies by category and Kalshi’s by market, and makers pay nothing on Polymarket.