WASHINGTON, D.C. — The number of higher‑earners caught in the United Kingdom’s £100,000 tax threshold has doubled over the past four years, according to HM Revenue & Customs data released this week, prompting concerns about labour‑supply distortions and investor sentiment.

HMRC figures show that 12,000 individuals fell into the “£100k tax trap” in the 2019‑20 tax year, rising to roughly 24,000 by 2023‑24. The marginal rate of 40 % on earnings above the limit, combined with a loss of personal allowance, has driven some to cut hours, decline promotions or make excess pension contributions to stay below the ceiling.

London’s FTSE 250 slipped 0.6 % on the news, while the broader FTSE 100 held steadier ground, reflecting investor worries that the tax cliff could suppress productivity among senior staff. Analysts at Barclays warned that the behavioural response may erode earnings growth in sectors reliant on skilled professionals.

In the United States, the Federal Reserve’s latest policy‑rate hike to 5.25 % has kept global bond yields elevated, pressuring the pound. Currency traders noted that the UK’s fiscal‑policy dilemma adds to the pound’s volatility, with the GBP/USD pair hovering near 1.25 after the report.

“The government must consider a smoother tapering of the personal‑allowance withdrawal to avoid unintended labour market effects,” said Treasury minister James Daly, who confirmed that a review of the threshold is under way but no timetable has been set.

Key Takeaways

• The affected population has risen from 12,000 to 24,000, a 100 % increase in four years.
• Some high‑earning workers are reducing hours or forgoing promotions to stay under the £100k limit.
• Market participants see the tax cliff as a risk to UK earnings growth and currency stability.

While the Treasury signals a possible reform, investors will watch closely for policy signals that could restore confidence in the UK’s labour market and mitigate the broader macro‑economic fallout.