FY stands for fiscal year: the twelve months a government or a company uses to count money. That year often does not start on 1 January. The US government starts its FY in October; a shop might start in April. People write FY2026, FY 2026, or FY26. Though actually, the number is often the year the period ends, so FY2026 can mean money-months that began in 2025 — which is why even fluent readers have to check. You meet FY in budgets, reports, and office mail, not in stories. In Taiwan a company or the government will say 會計年度 in Chinese, then often switch to FY in English slides.