What's new

7 September 2026

A new name and a new look: Hundred Summers

The app is now Hundred Summers — a name that says what the plan is for: a hundred summers, each one funded. A sunrise takes over as the mark, the palette warms to match, and everything else stays exactly where you left it: your data (still on your own device), your plan, your subscription and every calculator and guide. The web address is now hundredsummers.co.uk — old links and bookmarks keep working and redirect here.

7 September 2026

Would your retirement have survived 1929?

A new free interactive replays your pot and spending through every complete market window since 1928 — the 1929 crash, the 1937 relapse, the 1966–81 inflation grind, the 1973 oil shock, the 2000s lost decade and every quieter start between. Each window is a full UK simulation on the app's real backtest engine: that era's return and inflation deviations layered on your own assumptions, with your spending, tax bands and State Pension carried through the replayed inflation. A survival strip shows every start year's fate; click any year — or a famous crash — and watch that retirement's pot unfold year by year. Also fixed: the standalone calculator pages now carry the site's full top navigation on desktop.

7 September 2026

Built from what Britain actually asks: five calculators, three guides, and a new insight

We audited the questions asked most on the UK's personal-finance communities and built the answers. New calculators: the £100k childcare cliff (the 60% zone plus the support cliff at £100,001, and the pension contribution that often costs less than nothing), student loan overpayment (simulated to write-off — for most Plan 2 borrowers the honest answer is don't), your personal safe withdrawal rate (solved by projection, not asserted at 4%), the ISA bridge for early retirement (with pensions locked until they legally unlock), and debt payoff (avalanche vs snowball, with the difference priced). Three guides join them: the childcare cliff in full, inheriting money — the order of operations, and what a defined benefit pension is actually worth. And the Cashflow tab's insight rail now prices 'one more year': what one extra working year adds to your sustainable annual spending, from the same solver that draws the safe-to-spend line.

7 September 2026

Three life-event calculators and five new guides

The catalogue reaches 34 calculators and 17 guides. New calculators for the moments that compress years of tax planning into weeks: redundancy pay (the £30,000 exemption, the excess at real bands with the 60% trap flagged, and what paying it into your pension saves), care costs (the same figures the app's longevity scenarios charge, compounded at care inflation, with the £23,250 means test explained), and downsizing (capital freed after honest moving costs, priced as lifetime income). Five guides join them: pensions and inheritance tax from April 2027 — the biggest pension rule change in a decade, and why the old 'spend the pension last' doctrine no longer follows; which account to spend first in retirement; drawing retirement income as a couple (the coordination dividend the Household tab computes); the £10,000 MPAA trap; and the redundancy tax playbook.

7 September 2026

Eight more free calculators — the catalogue reaches 31

The final push to the most comprehensive free UK calculator catalogue we know of, all engine-backed: when can I retire (the app's own solver testing each candidate age with a full projection), self-employed tax (bands plus Class 4 NI, with the Class 2 abolition explained), rental income tax (including the April-2027 +2pp property surcharge almost no calculator models yet), marriage allowance (both sides of the transfer priced, not just the £252 headline), the pension tax-free lump sum (PCLS up front vs UFPLS slice-by-slice, under the £268,275 cap), investment bond gains (HMRC top-slicing done properly, onshore and offshore), the Lifetime ISA (25% bonus projected to 60, with the withdrawal penalty priced honestly at 6.25% of your own money), and mortgage repayments (the full amortisation, with the interest share most lenders don't lead with).

7 September 2026

Ten more free calculators — 23 in all

The catalogue reaches twenty-three, every one running on the same engine as the full plan: take-home pay (with your true marginal rate, 62% zone included), bonus tax, dividend tax on the April-2026 rates, the child benefit £60k–£80k clawback (and the pension contribution that restores it), student loans as the graduate tax they really are, pension projection with the fee drag priced, remortgaging with the term trap flagged, equity release with the compounding shown honestly, life cover by the transparent DIME method, and a life-expectancy estimator built on the same ONS-based model that sets your plan's horizon.

7 September 2026

Six more calculators, six more guides — and a sharper 7-year rule

The free-tools library doubles: calculators for buying missing NI years (the ~3-year breakeven, after tax), the 7-year gift rule (with the nil-rate-band ordering most explanations miss), mortgage overpaying vs investing (both routes' end wealth, compared without double-counting), how much you need to retire (solved by the real projection, not 25×), capital gains tax (gains stacked on income, as the law works), and pension carry-forward (each prior year tapered on its own income). Six guides join them, from sequence-of-returns risk told through real market history to care home fees. Building the 7-year calculator also caught and fixed an engine kindness: taper relief was being granted on gifts the nil-rate band already sheltered — the statutory rule is narrower, and the engine, Methodology page and Inheritance tab now apply it exactly.

7 September 2026

Three more free calculators, four more guides

The free-tools side of the site grows: an annuity calculator (indicative market rates with the real cost of spouse provision, guarantees, inflation-linking and enhanced health rates), a State Pension deferral calculator (the statutory ~5.8% a year uplift against the income you give up, with your honest breakeven age), and a FIRE calculator (Lean, Regular and Fat FI numbers plus Coast FI, on exactly the definitions the app's FIRE card uses). Alongside them, four new guides: the 60% tax trap between £100,000 and £125,140, UFPLS vs drawdown vs annuity, State Pension deferral, and FIRE in the UK — every load-bearing figure pinned against the engine's own functions so a rule change can't leave a page stale.

7 September 2026

Couples: the coordinated-drawdown what-if

The Household tab can now answer the question adviser software answers: what if you drew retirement income as one household instead of two individuals? Switch on the what-if and every shared retirement year's draw is split across both partners cheapest-taxable-pound-first — filling both personal allowances and both basic-rate bands, with the balancing cash moved between you (tax-free between spouses) — all through the same per-person tax engine as every other number. You see the tax saved in like-for-like years, any spending the uncoordinated plans couldn't fund that coordination rescues, and the net-worth difference at plan end, each stated honestly and separately. A pattern, not advice: coordinating changes whose name the wealth sits in.

7 September 2026

Explanations off now really clears the screen

The Settings → Explanations preference now governs far more of the app's helper text. The Overview's reality check keeps its score and one factual line while its explanation folds away; the risk-tab introduction, income-strategy and drawdown descriptions, estate-lever notes, plan-insight framing and a dozen other explanatory paragraphs now follow the setting too. What never hides: your figures, verdicts, warnings, honesty caveats and every 'this is education, not advice' line.

6 September 2026

Plan insights: what your projection already knows

The Cashflow tab gains an insights rail — engine-true observations in the spirit of the best budgeting apps, at lifetime scale: what cash growing below inflation costs you in real terms each year, the years your plan holds money outside tax wrappers while ISA allowance goes unused (with the dividend tax that costs, as a floor), and what your investment charges add up to across the plan — or an honest nudge if you're modelling a zero-cost portfolio, which no real portfolio is. Every figure comes from your own projection and stated assumptions; nothing is a recommendation.

5 September 2026

Broken references are now called out — events, mortgage links, lump-sum destinations

Delete an account that a planned event draws from and the plan used to fall back to general funds silently. Now the event is flagged in red where you edit it — naming the missing account — and the Overview shows a warning above your goals until the event points somewhere real again. The same audit covers the rest of your plan: a mortgage linked to a deleted property, an overpayment aimed at a deleted mortgage (which silently did nothing), and a tax-free lump sum destined for a deleted account — which the engine used to quietly reroute into a different account, and now honestly treats as spent, with a warning telling you so.

5 September 2026

A switch for backup-file encryption

Backup files — the automatic backup and manual exports — are AES-256-encrypted by default, and Settings now has a clear on/off switch instead of a passphrase prompt on every save. Turning it off saves plain, readable files (with a warning, and the connected backup file is rewritten immediately either way). Adviser sharing is not affected: it stays end-to-end encrypted regardless — that promise is not optional.

5 September 2026

The lifetime-cost lens: what each expense line really costs

The Expenses tab now prices every itemised line the way a lifetime plan should: your full plan re-run with that one line switched off, showing the payments plus everything they would have compounded into by the end of your plan — on your own growth, tax and drawdown rules, not a rule-of-thumb formula. A price tag, not a verdict: spending on what matters is what the plan is for.

5 September 2026

Cashflow: a safe-to-spend line and your tightest year

The cashflow chart now draws your sustainable spending level — the most you could spend in retirement and still fund every year, phased exactly like your own plan — against what you actually plan to spend, so the gap between the lines is your headroom at a glance. It also marks the plan's tightest year: where your accessible funds bottom out, and by how much.

4 September 2026

A slicker What If: success rates and spotlighting in scenario compare

The saved-scenario comparison now shows each scenario's Monte Carlo success rate beside net worth and money-lasts — every plan tested on the same market paths so the ranking is fair — and the overlay chart gained spotlight and hide controls, so comparing five scenarios no longer means reading spaghetti. Headline figures across the app now ease to their new values as you drag sliders, views show a live 'running the simulations' state instead of going blank, empty tabs now explain what they'll become with one button to the right place, and chart readouts pin to the top on phones so your finger never covers them.

3 September 2026

Couples: tax opportunities between your two plans

The Couples tab now spots where a couple's two tax positions leave money on the table — an unclaimed marriage allowance, pension contributions that would earn more relief routed through the higher earner, and retirement years where one partner's personal allowance sits unused. Each observation is computed from your own plans and quantified where it honestly can be; the projection itself never re-routes money between you.

3 September 2026

Two more free calculators: salary sacrifice, and ISA vs pension

Both run on the app's real tax-band and National Insurance functions, entirely in your browser: the salary sacrifice calculator shows what a pension contribution really costs (including the 60% relief zone between £100k and £125,140 and any employer NI pass-on), and the ISA-vs-pension comparison settles the classic question on your actual numbers.

3 September 2026

The stress test now taxes pension drawdown

Each simulated year's pension withdrawal is now grossed up for the income tax due on it, exactly as the main projection does — so a net spending need costs the simulation what it really costs. Success rates read honestly lower as a result (the demo plan drops from 64% to around 48%), and the historical backtest tightens for the same reason, with tax bands tracking each replayed era's price level the way income already did.

2 September 2026

Life & Care scenarios now run through the full engine

The Stress Test tab's four life-length and care scenarios used to be projected by a simplified untaxed model whose end-of-plan figures could sit far above the main projection's. Each scenario is now your actual plan re-projected by the same engine as every other number in the app — same tax, pensions, drawdown order and events — and 'runs out' honestly flags any year whose spending can't be funded.

2 September 2026

A cleaner look: crisp icons, softer cards, clearer verdicts

The app now uses one consistent set of crisp line icons throughout — navigation, page titles and card headers — instead of mixed emoji that render differently on every device. Goal cards state their verdict in plain FUNDED / AT RISK labels, and cards across the app get softer corners and shadows.

1 September 2026

The site grows up: calculators, guides and the app guide

hundredsummers.co.uk is now a real multi-page site: free in-browser calculators for pension drawdown and inheritance tax, plain-English guides, the full app walkthrough with narrated videos at /help/, and standalone pricing and tools pages — all linked from a proper navigation bar.

31 August 2026

Historical backtest: your plan through every market since 1928

The Stress Test tab now replays your full plan through every rolling window of market history from 1928 to 2023 — the 1929 crash, the 1966–81 inflation grind, the 2000s lost decade — and shows exactly which historical start years your plan would have survived.

31 August 2026

Choose your simulation count — up to 10,000 paths

A new Plan Assumption sets how many Monte Carlo paths the stress test runs (default 500, up to 10,000). The default is already statistically stable; raising it sharpens the tail percentiles.

30 August 2026

Methodology published in full

Every assumption behind the projections — tax rules, growth defaults, the market model, the backtest — is now public at /methodology.html, generated from the same code that runs the app. No other planning tool publishes its assumptions.

25 August 2026

Goals: timeline, likelihoods and what would fix it

The Overview's goals now show a timeline of when each goal needs money, how often each was funded across the market simulations, exactly where the money comes from, and — for anything off track — the specific change that would fix it.

21 August 2026

Accounts always carry an explicit tax wrapper

Every savings account now shows and stores its tax wrapper explicitly (ISA, GIA, cash, bonds, EIS/VCT…) instead of the engine inferring one — and when in doubt, the engine now assumes taxable, never tax-free.

17 August 2026

Advisers can propose changes — clients accept or reject

An adviser can send a proposed plan back to their client, end-to-end encrypted. The client sees an itemised diff of every change and explicitly accepts or rejects it — nothing touches their plan without their say-so.

16 August 2026

Every planned expense says exactly where the money comes from

Goal cards now break funding down — '£20k from the year's income, £150k drawn from your ISA' — using the engine's own ledger of what actually moved, and honestly flag anything the plan cannot fund when it falls due.

12 August 2026

A far more realistic market model

The stress test's simulated markets now move together like real ones: correlated equity, bond and property returns with fat-tailed shocks, and inflation that persists once it takes hold — validated against a century of market history. Success rates are more honest (and typically lower) than before.

5 August 2026

Fees, income shocks and target allocations

Per-account charges now drag on growth with a cost-of-fees comparison; income protection policies can be stress-tested against a loss-of-earnings scenario; and your risk profile suggests a target asset allocation to compare against what you actually hold.