FOR THE UNITED KINGDOM
TAKING THE UNCERTAINTY OUT OF LEGAL DEADLINES
Start CalculatingJournalistic, mistake-led guides to the quirks and traps that shift UK deadlines. For the rule definitions, see the technical reference, and for scenario walkthroughs, visit Use Cases.
The '3 months less 1 day' rule is one of the strictest deadlines in UK law. Miss it by a day and your claim is out - unless you know how ACAS conciliation pauses the clock.
Once a notice of adjudication lands, you have 7 days to appoint an adjudicator and 28 days until a binding decision. That timeline is deliberate - and unforgiving.
Every UK company director should know these dates. The annual accounts deadline is 9 months from your accounting reference date. The confirmation statement is due within 14 days of your anniversary. Miss them and penalties start immediately.
Section 21 notices can still be served until 30 April 2026. After that, every eviction needs a valid reason under Section 8. The notice periods and rules are changing completely.
Your council has 8 weeks to decide most planning applications, 13 weeks for major developments. When they miss these deadlines, you can appeal for non-determination - but there are tactical considerations.
The 31 January deadline is the one everyone knows. But there's also 31 October for paper returns, 31 July for payment on account, and a penalty structure that escalates faster than most people realise.
The 6-month inheritance tax deadline catches many executors off guard. You cannot wait for probate - IHT is due 6 months after the end of the month of death, whether or not you have access to the estate's funds.
If you only look at the bank holiday list, you miss the real planning story: the long stretches where nothing interrupts delivery - and the moments where one substitute day changes everything.
The Scottish courts can be closed on days that are not Scottish bank holidays, and different courts have different local privilege days. That is where UK-wide deadline instincts fail.
Most CPR deadline surprises come from a small set of quirks: short periods switch to working-day counting, clear days exclude both ends, and deemed service can quietly move your start date.
Most conveyancing delays aren't caused by one big problem - they're caused by small timing assumptions that compound across a chain.
Most people know Christmas and New Year. The deadlines slip on the extra days: 2 January, St Andrew's Day, St Patrick's Day, and the Twelfth.