Hundred Summers

Guides

Plain-English explainers of the mechanics behind UK retirement and tax planning — grounded in the same rules the Hundred Summers engine models. Education, not advice.

The 4% rule: what it misses for UK retirees
Where the famous retirement withdrawal rule comes from, why its US assumptions travel badly to the UK, and what a real projection tests instead — tax, the State Pension, and the market sequences that actually broke retirements.
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The pension annual allowance taper, explained
How the £60,000 pension annual allowance shrinks for high earners: adjusted income over £260,000, threshold income over £200,000, the £1-for-£2 taper down to £10,000 — with worked examples.
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The 60% tax trap: earning between £100,000 and £125,140
Why every pound between £100,000 and £125,140 is effectively taxed at 60% (62% with NI), how the personal allowance taper creates it, and why pension contributions in this zone get the best relief in the UK tax system.
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UFPLS, drawdown or annuity: the three ways to take pension income
How the 25% tax-free entitlement works differently under UFPLS and flexi-access drawdown, what crystallisation means, the £268,275 lump sum allowance, and where annuities fit — the mechanics behind the choice.
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FIRE in the UK: what the American playbook misses
The 25× rule and savings-rate maths transfer; the mechanics don't. The pension access age bridge, ISA-vs-pension sequencing, UK tax on the way out, and where Coast and Barista FI fit — the honest UK version.
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Deferring your State Pension: the honest breakeven
The permanent ~5.8% a year uplift for waiting, the income you give up, the roughly age-83 breakeven, and the tax angle that often matters more — the statutory mechanics, worked through honestly.
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Buying National Insurance years: the best deal in UK finance
Each Class 3 year costs about £900 and adds ~£359 a year of State Pension for life — a three-year breakeven. Who it helps, who it can't, and the checks to run before paying HMRC anything.
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The 7-year rule for gifts — and why taper relief disappoints
How Potentially Exempt Transfers really interact with the nil-rate band, why taper relief rarely helps gifts under £325,000, and the exemptions that work immediately — including the underused surplus-income rule.
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Overpay the mortgage or invest? The honest arithmetic
Overpaying earns your mortgage rate guaranteed and tax-free; investing has to beat it after fees, tax and nerve. How to compare the two properly — including what happens after the mortgage clears early.
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How much do I need to retire in the UK? Solved, not guessed
Why 25× spending, £500k-for-everyone and half-your-age rules all miss, what actually moves the number — tax, the State Pension, your dates — and how a real projection solves it.
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Sequence-of-returns risk, shown with real market history
Two retirees earn the same average return and one runs out of money: why the order of returns dominates retirement outcomes, which historical cohorts it broke, and how to test a plan against it honestly.
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Care home fees: the numbers nobody explains until it's urgent
What care actually costs, the £23,250 means-test line and when the home counts, why councils pay less than you would, and how to stress-test a plan against a late-life care phase.
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Pensions and inheritance tax from April 2027
The biggest pension rule change in a decade: unused pension pots join the estate for inheritance tax from April 2027 — what changes, the double-tax effect after 75, and how it rewrites the 'spend the pension last' doctrine.
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Which account to spend first in retirement
ISA, pension, general account — the order you draw them decides how much tax retirement pays. The mechanics of filling the personal allowance, the GIA-first doctrine, and how April 2027 rewrites the classic advice.
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Drawing retirement income as a couple: the coordination dividend
Two personal allowances, two basic-rate bands, tax-free transfers between spouses — why the same household income can cost thousands less when drawn as a couple, and how Hundred Summers computes the split.
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The MPAA: the £10,000 trap that outlasts the decision that sprang it
Take one flexible pension withdrawal and your annual allowance drops from £60,000 to £10,000 — permanently, with no carry-forward. What triggers the Money Purchase Annual Allowance, what doesn't, and who it ambushes.
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Redundancy: the tax playbook
The £30,000 exemption, what PILON really is, why the excess lands in your worst tax year, and the pension move that can save 40–60% — the decisions that must be made before the settlement agreement is signed.
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The £100k childcare cliff: the worst-designed threshold in UK finance
Cross £100,000 of adjusted net income by £1 and you lose all free childcare hours and Tax-Free Childcare — on top of the 60% tax zone. How the cliff works, which parent counts, and the pension escape route.
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Inheriting money: the order of operations
A lump sum arrives — inheritance, redundancy, a house sale. The unhurried sequence: debt, buffer, wrappers, the tax on what the money earns next, and the £2,880 trick for a non-earning partner.
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What a defined benefit pension is actually worth
NHS, teachers, civil service, old company schemes — why £10,000/yr of DB pension is worth more than most people's entire DC pot, how to compare added-pension offers, and why transferring out is almost always wrong.
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Hundred Summers. Education, not regulated financial advice; projections and results are illustrations, not guarantees.
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