How Polymarket Works - What the IRD Sees on the Blockchain
Polymarket is an on-chain prediction market platform where you buy and sell outcome shares using USDC. When a market settles, shares on the winning side are redeemed at $1 each. Shares on the losing side expire worthless. Buying, trading, and redeeming these shares can all create taxable events depending on your jurisdiction.
New Zealand's position is distinctive. There is no general capital gains tax - instead, the tax system applies income tax to gains from property acquired for the purpose of disposal or resale or profit. The IRD has not issued specific guidance on prediction markets. USDC is treated as property under the IRD's general guidance on cryptocurrency. The NZ tax year runs April 1 to March 31, with a filing deadline of July 7 for individuals.
How New Zealand Taxes Polymarket Profits
New Zealand's approach to trading gains is intent-based. The key question is: was the asset acquired for the purpose of disposal at a profit? This applies to prediction market shares just as it applies to shares, property, or cryptocurrency.
- Profit-motivated trading: If you entered Polymarket markets with the profit-making purpose - selecting markets based on analysis, expecting positive returns - your net gains are likely taxable as income at your marginal rate. Rates range up to 39% for income over NZ$180,000.
- Recreational or incidental activity: If your trading was genuinely recreational and profit was incidental to participation, it may fall outside the income tax net. In practice, this is a high bar for systematic traders.
- Loss deductibility: If your activity is taxable, losses from Polymarket may offset other taxable income. Consistency matters - you cannot treat gains as exempt and claim losses.
The IRD has no specific guidance on prediction markets. The intent-based approach applied to shares and other financial instruments is the closest applicable framework. Most active Polymarket traders - who select markets analytically and track their positions - would likely satisfy the profit-making intent test.
The USDC Layer - Disposal Events Under NZ Law
Under NZ crypto guidance, USDC is property. The same intent-based analysis that applies to Polymarket shares applies to USDC. For most active traders, USDC functions as a trading currency for Polymarket rather than a standalone investment, but the IRD could consider USDC disposals separately.
- USDC purchases: cost basis established at the NZD price at time of acquisition
- Depositing USDC to Polymarket: wallet transfer only, not a disposal
- Withdrawing USDC from Polymarket: wallet transfer only, not a disposal
- Converting USDC back to NZD: disposal event - potentially taxable if acquired for the purpose of resale
- USDC as functional currency: if USDC was merely a conduit for Polymarket activity rather than a profit-motivated acquisition in its own right, the taxability of USDC disposals may differ - consult a tax adviser for significant balances
What DYOR.tax Calculates for NZ Filers
The calculator scans your Polymarket proxy wallet to identify every trade, redemption, and settlement. For NZ traders it applies the income approach with the April-March tax year boundary, producing output organized for IRD review.
- Proxy wallet scan for all trades and settlements
- Income approach applied per NZ intent-based framework
- USDC disposals tracked with the April 1 to March 31 NZ tax year
- Market-by-market P&L organized for IRD review
- Optional History CSV enrichment for deposits and withdrawals
NZ Filing Requirements for Polymarket
If your Polymarket activity is taxable, the relevant form is the IR3 Individual Tax Return. Taxable trading income is reported under "other income" from trading activity. USDC gains, if taxable, are also included in the IR3.
- Tax year: April 1 to March 31
- Deadline: July 7 following the tax year end
- Extended deadlines: if you use a tax agent, extended filing deadlines may apply
- Records: keep transaction records for 7 years
- Form: IR3 Individual Tax Return, other income section
Common Polymarket Tax Mistakes in New Zealand
- Assuming no tax applies because "NZ has no CGT": income tax applies to profit-motivated trading activity. The absence of a general CGT regime does not mean trading gains are untaxed.
- Inconsistent treatment of wins and losses: if you treat gains as taxable, losses must also be deductible under the same framework. You cannot cherry-pick.
- Ignoring USDC disposals: converting USDC back to NZD may be a taxable event if you acquired the USDC for the purpose of resale.
- Not keeping entry and settlement prices: IRD may request records substantiating your cost basis for each market position.
- Using the wrong tax year boundary: NZ tax year ends March 31, not December 31 or June 30. Positions settled between April 1 and March 31 belong to that NZ tax year.
Related Resources
For broader NZ crypto tax context, the New Zealand crypto tax calculator covers the income approach, the March 31 tax year boundary, and IR3 filing. The Polymarket and Kalshi tax guide covers the profit-making purpose test across jurisdictions, and the NZ crypto tax deadline page has key IRD filing dates.
For Polymarket traders in other countries: USA - UK - Canada - Australia - India - South Africa
Back to the Polymarket tax calculator main page.