The UK tax year runs April 6 to April 5, not January to December. That's not just a calendar quirk — it's the dividing line for your dividend tax bill. With 26 days left in the 2025/26 tax year, there are two things working together that make this boundary uniquely consequential. First, your £500 dividend allowance resets on April 6 and doesn't carry forward. Any unused portion on April 5 is gone forever — most brokers show you calendar-year totals, so you might not even know where you stand. Second, dividend tax rates go up on April 6: basic rate from 8.75% to 10.75%, higher rate from 33.75% to 35.75%. But the rule that really matters is this: HMRC doesn't look at when a stock goes ex-dividend. It looks at when the payment actually lands in your account. A March ex-date can mean a May payment — landing you in the new tax year at higher rates. We walk through real examples with NatWest and HSBC, explain why this gap exists, and show you how to check your allowance position and consider a Bed and ISA strategy before the deadline closes.From the team behind Nestor – Dividend Trackerhttps://www.nestordividendtracker.co.uk