YES if the 18% or 24% main rate (or either residential property rate) is increased, with any start date. Changes only to reliefs, allowances or carried interest resolve NO. Polymarket priced a CGT increase at 61% on 21 Sep 2026.

Resolution. Resolves YES if the measure is announced in the Chancellor's Budget speech on 28 October 2026 or appears in the Budget documents HM Treasury publishes that day (the Budget document, the policy decisions table, the policy costings, or the Overview of Tax Legislation and Rates). A measure announced earlier counts if those documents confirm it. A consultation, review or call for evidence alone resolves NO.

This market closes at 12:00 UTC on Budget day, 30 minutes before the speech is due to begin, because measures resolve as the Chancellor announces them.

The creator may trade in this market. Resolution follows the sources named above.

If the Budget moves to another date in 2026, this market follows it and the close time moves with it. If no Budget is delivered by 31 December 2026, resolves N/A. Created by Max Ghenis of PolicyEngine (https://www.policyengine.org/uk) as a public record of what PolicyEngine expected before the Budget.

Clarification, 11 October 2026. A new main rate above 24% that applies to gains currently taxed at 18% or 24% (for example a higher rate for additional-rate taxpayers, or for gains above a set amount) counts as an increase, as does a higher main rate for one class of asset. A rate increase counts even if it comes with a new relief, allowance or indexation. Changes only to the Business Asset Disposal Relief or Investors' Relief rates, the annual exempt amount or carried interest still resolve NO. The creator holds 90.6 NO shares in this market. Where the existing words left a choice, the reading above goes against that position.