Polymarket vs Polymarket US: one brand, two exchanges, no shared book

Two exchanges that share a name and nothing else

The two cards above carry the same logo and the same vendor field, and a reader who has seen one has seen neither. Polymarket is operated by Adventure One QSS, Inc.: a self-custody central limit order book on Polygon, collateralised in pUSD — an ERC-20 backed one-for-one by USDC and enforced on-chain — with outcome shares held as ERC-1155 tokens in your own wallet. Polymarket US is operated by QCX LLC, which the CFTC's own record shows designated as a contract market on 9 July 2025. It clears through QC Clearing LLC, holds US dollars in a customer account its own FAQ says is kept separate from operating funds, and reaches you through an app published by a third company, PM US Tech.

The international card puts it in one line: the two share a brand rather than an operator, a regulator, a custody model, a fee schedule or a resolution authority. What neither card says in one place is the consequence a trader feels first.

There is no shared order book and no shared liquidity. Each card describes one book, its own. The international book matches orders from wallets holding pUSD; the US book matches orders from identity-verified participants of a designated contract market holding dollars at a clearing house, and that book is wiped weekly — every Thursday from 02:00 to 04:00 ET the US exchange cancels every open order, answers 503 on its API and reopens with empty books. A counterparty on one is not a participant on the other, and the two collateral units are not the same money. So when the same-looking question shows two prices, those are two crowds pricing two contracts, not one market quoted twice; nothing on either card says one price references the other.

The app in the store is the American one. The international card records that the iOS and Android apps are published for the US store and carry the Polymarket US product, and that no official app is listed in the international storefronts it checked. Outside the United States the international platform is a web application. A reader who downloads "Polymarket" and a reader who opens the website may be looking at different exchanges without either noticing.

Who may use which is settled before anything else

Most comparisons end on jurisdiction. This one starts there, because for almost every reader it removes the choice.

A US reader has one option. The international Terms of Use, effective 11 August 2026, bar trading by anyone resident, located or incorporated in the United States, in capitals, with "THERE ARE NO EXCEPTIONS". Reading is still permitted, and the live site tells a US visitor to switch to polymarket.us. Using a VPN to get round it is prohibited, and the stated consequence is that the wallet is put into close-only mode. Polymarket US is the mirror: US residents, at least 18 or the higher age their state sets, and no excluded state named in either document its card could open.

A reader outside the United States has at most one option, and often none. Polymarket US makes no claim of availability anywhere else: its terms make no representation that the app is available in any specific location, and its funding rails are US debit cards, ACH and domestic wires. The international platform restricts by physical location rather than residency, according to its help page last updated 14 August 2026 — though its Terms, as above, also reach residence for the United States. That page names 39 restricted countries plus Alberta, British Columbia, Ontario and Quebec and the Crimea, Donetsk and Luhansk regions, under three statuses that answer two different questions:

• Fully blocked, opening nothing: the United States, the United Kingdom, Germany, France, Italy, the Netherlands, Belgium, Ireland, Australia, New Zealand, Japan and Brazil, among others.
• Close-only, exiting but not opening: Singapore, Poland, Thailand and Taiwan.
• Hold to resolution: Germany, whose existing positions must run to settlement before funds can be withdrawn.

So a reader in London, Paris or Sydney has neither of these two. A reader in Singapore can close what they already hold on the international platform and open nothing on either. The list is less settled than a bulleted summary makes it look: Polymarket's Terms name Hungary and Slovenia where the help centre names Brazil, Japan, Malta and Burundi instead, and the Polymarket CLOB API card, reading the same restrictions page on 4 October 2026, records Ireland as close-only on the web app alone where the venue card, read on 19 September, has it fully blocked. Read the help centre on the day. Why a venue is unavailable where you are covers the four mechanisms that get called one word.

Identity is the other half of who may use it. The international platform runs no identity check at signup: a click-through attestation that you are not a US person, not in a restricted jurisdiction and not on a VPN, plus a reactive path — an ID and proof of address in a non-restricted jurisdiction, within 14 days — used when an account is flagged. Polymarket US makes identity verification mandatory and puts it before your first deposit: name, date of birth and residential address, then a government ID and selfie where the automatic check fails, with manual review quoted at three to five business days.

How money gets in and out of each

The custody difference is not abstract. It decides what a deposit is, what a withdrawal is, and how many steps lie between a resolved position and money you can spend.

On the international platform there is no balance to withdraw, only tokens to redeem and move. You fund in USDC through an on-ramp — the card names Coinbase and MoonPay — which charges its own fee; Polymarket charges none to deposit or withdraw. Getting out is three acts, as how money gets back out lays them out from Polymarket's own documentation. Redeem after resolution, which burns your outcome tokens and returns pUSD. Unwrap and swap pUSD into native USDC through a named Uniswap v3 pool, which the documentation warns can be exhausted. Then bridge to the token and chain you want. Polymarket says it charges no withdrawal fee and publishes no worked withdrawal quote; the one worked example in its bridge documentation is a deposit, 10 USDC into pUSD, and returns 9.94 — 2 cents of gas, a 0.3% line labelled bridge fee, 0.1% fill cost and 0.05% swap impact — which is the published measure of what a hop through the bridge costs. Over 50,000 dollars the documentation suggests splitting the withdrawal, and the only off-ramps it names, Coinbase and MoonPay, charge their own: MoonPay's European disclosure puts a sell by bank transfer at up to 1%. None of that is in a fee schedule. And a jurisdiction status can reach money already committed: close-only releases capital when you sell, hold-to-resolution does not release it until the contract ends.

On Polymarket US money leaves the way it came in. Deposits are debit card, ACH or wire. Card and ACH take three to four business days to clear, a wire one, and you can trade with funds in flight but not withdraw them. Withdrawals are documented as free, go back to the original funding source only — never a new or third-party account — and are processed first-in-first-out against the deposits that funded them. Promotional credit is a trading credit rather than cash, and the venue's own two pages disagree about whether it can ever leave; the card's advice is to assume the stricter one.

Nothing connects the two. Polymarket US lists no crypto rail in either direction, and the international platform holds no dollars. Neither card describes moving a balance or a position from one to the other, so a trader who wanted to would be closing on one and opening on the other — and on the two cards' own eligibility rules, there is no reader who may trade on both.

The fee shape is shared; the coefficients and the maker side are not

economics.fees_taker on every card is the effective taker fee at 50 cents as a percentage of the $1 payout. The two cards read Polymarket 1.25 and Polymarket US 1.74. The maker field reads null on the international card and −0.31 on the US one. Those four numbers are the comparable part; what sits behind them needs a sentence each.

On the taker side the base is the same. Both venues charge a coefficient times contracts times price times one-minus-price — a rate on expected earnings, not on the fill, peaking at the midpoint and falling towards nothing at both ends. What differs is the coefficient and what it varies by. The international platform sets it by category: 0.07 on crypto, 0.05 on sports, economics, culture, weather and the general bucket, 0.04 on finance, politics, mentions and tech, and zero on geopolitics. Polymarket US has one coefficient, 0.0695, under the schedule effective from 25 September 2026, with two exceptions the card records — a separate, steeper curve on combos, and an announced change taking Table Tennis to 0.10 from 7 October 2026.

At 50 cents, then, category by category: crypto 1.75% against 1.74%, a hundredth of a point apart; sports and the general bucket 1.25% against 1.74%; politics and finance 1.00% against 1.74%; and geopolitics free against 1.74%. At the midpoint the international platform is cheaper for a taker in every category but crypto, where the two are level. Polymarket US pays takers back weekly off the previous calendar month's notional — 10% from $250,000, 25% from $1 million, 50% from $10 million — which takes its 1.74% to about 1.57%, 1.31% and 0.87%. The international card mentions a tiered taker rebate and prints no tiers for it.

On the maker side the percentages are percentages of different things. On the international platform makers are never charged, and their rebate is a share of the taker fees collected — 20% on crypto, 15% on sports, 25% on the other charged categories — paid daily out of that pool. What you receive depends on what takers paid and your share of the pool, so there is no per-fill figure to normalise, which is why the field is null rather than negative. On Polymarket US the maker rebate is a coefficient, −0.0125, applied to the maker's own fill and credited at the moment of the fill: 0.31% of the payout at 50 cents. One is a cut of a pool, the other a price on your order.

The units of payment differ too. International fees are charged per share in pUSD. US fees are in dollars, rounded to the cent with banker's rounding, and the exchange's own FAQ says a small fill can round to zero.

For most readers none of this chooses a venue, because residence already has. It matters to anyone reading the two prices side by side — the cost of acting on each differs by category before the prices themselves are compared — and to anyone budgeting a resting-order book on the US exchange. The prediction market fee calculator applies both schedules to your own price and size, and what a trade actually costs explains the units.

Who decides the outcome, and why the same question is two contracts

This is the field on which the international card says the two products are least alike.

Internationally, Polymarket decides nothing. The UMA optimistic oracle does. An outcome is proposed against a bond, typically 750 pUSD — since 5 September 2025 only by whitelisted addresses on markets where Polymarket applies UMA's proposer whitelist. Anyone may dispute within a two-hour challenge window. One dispute sends the question to a second proposal round; a second escalates to a vote of UMA token holders, which the company cannot overturn. A rare Unknown outcome pays 50 cents to each side. Clarifications are published on-chain and cannot change the intent of the question.

On Polymarket US the exchange decides, and that is the end of it. Its rulebook names the exchange as the Source Agency, determining each contract against primary, secondary and tertiary sources listed in that contract's terms; sources not listed have no effect. Rule 10.4 lets named officers review an outcome at sole discretion and states the company's determinations are final. Rule 10.5 settles contracts about a person who dies or is incapacitated at last traded prices, not subject to review. Rule 10.3 lets the company modify a contract's specifications after you hold it, including the settlement date, the payout condition and the interpretation of resolution criteria.

Neither offers an appeal to the company. Only one offers anything a third party can enter — a bond and two hours on the international platform. Who decides the outcome sets both beside the other venues.

The consequence for a reader comparing the two prices: the same headline is two contracts. Each venue writes its own terms, so the named source, the close, the fallback when the question cannot be answered and the authority that applies them are set separately — and nothing on either card says the two are drafted to match. They do not share an identifier either: the international platform addresses an outcome by token, the US exchange by a market slug such as aec-nfl-lac-ten-2025-11-02. Line them up on the rule text, never the title, as how to match the same question across venues sets out. The listings cannot be lined up by count either: the US card records 2,611 open sports events and 1,167 open politics events on its public API on 19 September 2026, and the international card prints a list of categories and no counts.

For developers, two integrations, not one with a flag

Nothing written for one reaches the other; the international card and the US API card both say so in nearly those words.

The international platform splits its interfaces across several cards: the Polymarket Gamma API for markets and metadata, the Polymarket CLOB API for the book and order placement, and the Polymarket Data API for trades, positions and holders. Reading the book takes nothing. Placing an order takes a Polygon wallet, an EIP-712 signature to derive credentials, an HMAC-SHA256 signature on every request and a pUSD balance — and no identity check. There is no test environment. The current Python client is polymarket-client; py-clob-client is archived. The CLOB card's warning matters most to a US developer: the read endpoints answer from anywhere, so a successful read proves nothing about whether you may trade.

Polymarket US has one API card, the Polymarket US API, on two hosts: a keyless public gateway for markets, books, settlement prices and search, and an authenticated host for orders, portfolio and balances, signed with an Ed25519 key in three request headers. Getting that key means installing the iOS app, opening an account and passing identity verification — there is no developer path around the app. The official SDKs are the Polymarket US Python SDK and the Polymarket US TypeScript SDK, both installed as polymarket-us, and both registry releases date from January 2026 while their repositories carry commits from September. Plan around the Thursday window: orders cancelled, 503s, empty books.

Different hosts, different identifiers, different signing, a wallet on one side and a KYC'd account on the other. What each Polymarket API holds maps the international set in full.

What the two cards rest on

Both cards carry 19 September 2026 as the verification date for availability and for pricing, so the jurisdiction facts on this page were read on the same day for both. The fee text is not level: the US card's fee section quotes a schedule effective from 25 September and an announcement read on 7 October, so on fees its side of this page is roughly three weeks fresher than the international side, whose fee table was read on 19 September. The international restrictions page also moved under the catalogue's feet — by 21 September its country notes and close-only list no longer rendered outside a browser, so the Germany sentence above is the 19 September reading.

Which one, and when

Decide by where you are first, because the two cards leave no overlap.

In the United States, Polymarket US — and your real comparison is with Kalshi. The international platform is view-only to you, and a VPN breaches its Terms and puts the wallet into close-only mode. Read Kalshi vs Polymarket US vs Robinhood next: that is the choice a US reader actually has, and it is where the maker rebate and the Thursday window are weighed against a rival exchange rather than against a sibling you cannot use.

Outside the United States, the international Polymarket where your physical location is not on its lists, because Polymarket US claims nothing outside the US and its rails are US-only. Check the help centre on the day you fund, not a summary of it, and ask the close-only question before the fee question: in Singapore, Poland, Thailand or Taiwan you may exit and not open, and in Germany a position is held to resolution. If neither is open to you, the choice is among the offshore venues in Polymarket vs Limitless vs Myriad.

Then by what you need from the venue you are left with. If being able to contest a resolution matters, only the international platform has a process — a bond, two hours and a vote — and a US reader who needs that will not find it in this pairing. If you need dollars back on a known bank rail, Polymarket US returns them to the source that funded them, free and in deposit order, where the international exit is redeem, swap and bridge, best quoted before you start. If you are reading both prices for research or a dashboard, both are readable without a key from anywhere; treat them as two contracts with two rulebooks and match them on the rules, never the brand.