{
  "title": "Hundred Summers validation pack",
  "taxYear": "2026/27",
  "tolerance": 1,
  "page": "https://hundredsummers.co.uk/validation.html",
  "cases": [
    {
      "id": "it-30k",
      "area": "Income tax: England, Wales and Northern Ireland",
      "title": "Salary £30,000",
      "steps": [
        "£30,000 − £12,570 personal allowance = £17,430 taxable",
        "£17,430 at 20% = £3,486.00"
      ],
      "workedByHand": 3486,
      "engine": 3486,
      "difference": 0,
      "withinTolerance": true,
      "engineFigure": "Projection, first year: income tax",
      "rule": "gov.uk: Income Tax rates and Personal Allowances",
      "ruleUrl": "https://www.gov.uk/income-tax-rates",
      "note": ""
    },
    {
      "id": "it-60k",
      "area": "Income tax: England, Wales and Northern Ireland",
      "title": "Salary £60,000",
      "steps": [
        "£60,000 − £12,570 = £47,430 taxable",
        "Basic rate: £37,700 at 20% = £7,540.00",
        "Higher rate: £9,730 at 40% = £3,892.00",
        "Total £11,432.00"
      ],
      "workedByHand": 11432,
      "engine": 11432,
      "difference": 0,
      "withinTolerance": true,
      "engineFigure": "Projection, first year: income tax",
      "rule": "gov.uk: Income Tax rates and Personal Allowances",
      "ruleUrl": "https://www.gov.uk/income-tax-rates",
      "note": ""
    },
    {
      "id": "it-110k",
      "area": "Income tax: England, Wales and Northern Ireland",
      "title": "Salary £110,000: personal allowance tapered",
      "steps": [
        "Allowance falls £1 for every £2 over £100,000: £12,570 − £5,000 = £7,570",
        "£110,000 − £7,570 = £102,430 taxable",
        "Basic rate: £37,700 at 20% = £7,540.00",
        "Higher rate: £64,730 at 40% = £25,892.00",
        "Total £33,432.00"
      ],
      "workedByHand": 33432,
      "engine": 33432,
      "difference": 0,
      "withinTolerance": true,
      "engineFigure": "Projection, first year: income tax",
      "rule": "gov.uk: Income Tax rates: income over £100,000",
      "ruleUrl": "https://www.gov.uk/income-tax-rates/income-over-100000",
      "note": ""
    },
    {
      "id": "it-150k",
      "area": "Income tax: England, Wales and Northern Ireland",
      "title": "Salary £150,000: no personal allowance",
      "steps": [
        "No personal allowance above £125,140",
        "Basic rate: £37,700 at 20% = £7,540.00",
        "Higher rate: £125,140 − £37,700 = £87,440 at 40% = £34,976.00",
        "Additional rate: £150,000 − £125,140 = £24,860 at 45% = £11,187.00",
        "Total £53,703.00"
      ],
      "workedByHand": 53703,
      "engine": 53703,
      "difference": 0,
      "withinTolerance": true,
      "engineFigure": "Projection, first year: income tax",
      "rule": "gov.uk: Income Tax rates: income over £100,000",
      "ruleUrl": "https://www.gov.uk/income-tax-rates/income-over-100000",
      "note": ""
    },
    {
      "id": "sit-50k",
      "area": "Income tax: Scotland",
      "title": "Salary £50,000, Scottish taxpayer",
      "steps": [
        "Starter £12,571–£16,537: £3,967 at 19% = £753.73",
        "Basic £16,538–£29,526: £12,989 at 20% = £2,597.80",
        "Intermediate £29,527–£43,662: £14,136 at 21% = £2,968.56",
        "Higher £43,663–£50,000: £6,338 at 42% = £2,661.96",
        "Total £8,982.05"
      ],
      "workedByHand": 8982.05,
      "engine": 8982,
      "difference": -0.05,
      "withinTolerance": true,
      "engineFigure": "Projection, first year: income tax",
      "rule": "gov.uk: Scottish Income Tax 2026 to 2027",
      "ruleUrl": "https://www.gov.uk/scottish-income-tax",
      "note": ""
    },
    {
      "id": "sit-80k",
      "area": "Income tax: Scotland",
      "title": "Salary £80,000, Scottish taxpayer",
      "steps": [
        "Starter, basic and intermediate bands as above: £753.73 + £2,597.80 + £2,968.56 = £6,320.09",
        "Higher £43,663–£75,000: £31,338 at 42% = £13,161.96",
        "Advanced £75,001–£80,000: £5,000 at 45% = £2,250.00",
        "Total £21,732.05"
      ],
      "workedByHand": 21732.05,
      "engine": 21732,
      "difference": -0.05,
      "withinTolerance": true,
      "engineFigure": "Projection, first year: income tax",
      "rule": "gov.uk: Scottish Income Tax 2026 to 2027",
      "ruleUrl": "https://www.gov.uk/scottish-income-tax",
      "note": ""
    },
    {
      "id": "ni-30k",
      "area": "National Insurance",
      "title": "Employee, salary £30,000 (Class 1)",
      "steps": [
        "£30,000 − £12,570 primary threshold = £17,430",
        "£17,430 at 8% = £1,394.40"
      ],
      "workedByHand": 1394.4,
      "engine": 1394,
      "difference": -0.4,
      "withinTolerance": true,
      "engineFigure": "Projection, first year: employee NI",
      "rule": "gov.uk: National Insurance rates and categories",
      "ruleUrl": "https://www.gov.uk/national-insurance-rates-letters",
      "note": ""
    },
    {
      "id": "ni-60k",
      "area": "National Insurance",
      "title": "Employee, salary £60,000 (Class 1)",
      "steps": [
        "£12,570 to £50,270: £37,700 at 8% = £3,016.00",
        "Above £50,270: £9,730 at 2% = £194.60",
        "Total £3,210.60"
      ],
      "workedByHand": 3210.6,
      "engine": 3211,
      "difference": 0.4,
      "withinTolerance": true,
      "engineFigure": "Projection, first year: employee NI",
      "rule": "gov.uk: National Insurance rates and categories",
      "ruleUrl": "https://www.gov.uk/national-insurance-rates-letters",
      "note": ""
    },
    {
      "id": "ni-c4-40k",
      "area": "National Insurance",
      "title": "Self-employed, profits £40,000 (Class 4)",
      "steps": [
        "£40,000 − £12,570 lower profits limit = £27,430",
        "£27,430 at 6% = £1,645.80"
      ],
      "workedByHand": 1645.8,
      "engine": 1646,
      "difference": 0.2,
      "withinTolerance": true,
      "engineFigure": "Projection, first year: NI",
      "rule": "gov.uk: Self-employed National Insurance rates",
      "ruleUrl": "https://www.gov.uk/self-employed-national-insurance-rates",
      "note": ""
    },
    {
      "id": "sav-starting-rate",
      "area": "Savings and dividend tax",
      "title": "Wages £16,000, savings interest £3,000",
      "steps": [
        "Other income above the personal allowance: £16,000 − £12,570 = £3,430",
        "Starting rate for savings left: £5,000 − £3,430 = £1,570 at 0%",
        "Personal Savings Allowance (basic-rate taxpayer): £1,000 at 0%",
        "Remaining £3,000 − £1,570 − £1,000 = £430 at 20% = £86.00"
      ],
      "workedByHand": 86,
      "engine": 86,
      "difference": 0,
      "withinTolerance": true,
      "engineFigure": "Engine: calcSavingsDividendTax (as the projection calls it)",
      "rule": "gov.uk: Tax on savings interest: how much is tax-free",
      "ruleUrl": "https://www.gov.uk/apply-tax-free-interest-on-savings/how-much-is-tax-free",
      "note": "gov.uk's own worked example (£16,000 of wages leaves £1,570 of starting rate), extended with more interest."
    },
    {
      "id": "div-40k",
      "area": "Savings and dividend tax",
      "title": "Salary £40,000, dividends £10,000",
      "steps": [
        "£500 dividend allowance at 0%, leaving £9,500",
        "Basic-rate band left: £50,270 − £40,000 = £10,270, so all £9,500 is basic rate",
        "£9,500 at 10.75% = £1,021.25"
      ],
      "workedByHand": 1021.25,
      "engine": 1021.25,
      "difference": 0,
      "withinTolerance": true,
      "engineFigure": "Engine: calcSavingsDividendTax (as the projection calls it)",
      "rule": "gov.uk: Tax on dividends",
      "ruleUrl": "https://www.gov.uk/tax-on-dividends",
      "note": ""
    },
    {
      "id": "cgt-40k",
      "area": "Capital Gains Tax",
      "title": "Gain £20,000, income £40,000",
      "steps": [
        "£20,000 − £3,000 annual exempt amount = £17,000 taxable gain",
        "Basic-rate band left: £37,700 − (£40,000 − £12,570) = £10,270 at 18% = £1,848.60",
        "The other £6,730 at 24% = £1,615.20",
        "Total £3,463.80"
      ],
      "workedByHand": 3463.8,
      "engine": 3464,
      "difference": 0.2,
      "withinTolerance": true,
      "engineFigure": "Engine: calcCGT (as the projection calls it)",
      "rule": "gov.uk: Capital Gains Tax rates and allowances",
      "ruleUrl": "https://www.gov.uk/capital-gains-tax/rates",
      "note": ""
    },
    {
      "id": "cgt-low-income",
      "area": "Capital Gains Tax",
      "title": "Gain £50,000, income £5,000",
      "steps": [
        "£50,000 − £3,000 = £47,000 taxable gain",
        "Income is below the personal allowance, but unused allowance cannot be set against gains: the whole £37,700 basic-rate band is left, no more",
        "£37,700 at 18% = £6,786.00",
        "£9,300 at 24% = £2,232.00",
        "Total £9,018.00"
      ],
      "workedByHand": 9018,
      "engine": 9018,
      "difference": 0,
      "withinTolerance": true,
      "engineFigure": "Engine: calcCGT (as the projection calls it)",
      "rule": "gov.uk: Capital Gains Tax rates and allowances",
      "ruleUrl": "https://www.gov.uk/capital-gains-tax/rates",
      "note": ""
    },
    {
      "id": "cgt-property-sale",
      "area": "Capital Gains Tax",
      "title": "Selling a let property: £150,000 gain, no other income",
      "steps": [
        "Bought £150,000, sold £300,000: £150,000 gain; not the main home, so no private residence relief",
        "£150,000 − £3,000 = £147,000 taxable gain",
        "£37,700 at 18% = £6,786.00",
        "£109,300 at 24% = £26,232.00",
        "Total £33,018.00"
      ],
      "workedByHand": 33018,
      "engine": 33018,
      "difference": 0,
      "withinTolerance": true,
      "engineFigure": "Projection: CGT charged in the sale year",
      "rule": "gov.uk: Capital Gains Tax rates and allowances",
      "ruleUrl": "https://www.gov.uk/capital-gains-tax/rates",
      "note": ""
    },
    {
      "id": "aa-taper",
      "area": "Pensions: allowances and tax-free cash",
      "title": "Tapered annual allowance: adjusted income £300,000",
      "steps": [
        "Threshold income £220,000 is over £200,000, so the taper applies",
        "Allowance falls £1 for every £2 of adjusted income over £260,000: (£300,000 − £260,000) ÷ 2 = £20,000",
        "£60,000 − £20,000 = £40,000"
      ],
      "workedByHand": 40000,
      "engine": 40000,
      "difference": 0,
      "withinTolerance": true,
      "engineFigure": "Engine: calcTaperedAnnualAllowance",
      "rule": "gov.uk: Tax on your private pension: annual allowance",
      "ruleUrl": "https://www.gov.uk/tax-on-your-private-pension/annual-allowance",
      "note": ""
    },
    {
      "id": "aa-floor",
      "area": "Pensions: allowances and tax-free cash",
      "title": "Tapered annual allowance: adjusted income £400,000",
      "steps": [
        "Reduction (£400,000 − £260,000) ÷ 2 = £70,000 would take it below zero",
        "The allowance never falls below the £10,000 minimum"
      ],
      "workedByHand": 10000,
      "engine": 10000,
      "difference": 0,
      "withinTolerance": true,
      "engineFigure": "Engine: calcTaperedAnnualAllowance",
      "rule": "gov.uk: Tax on your private pension: annual allowance",
      "ruleUrl": "https://www.gov.uk/tax-on-your-private-pension/annual-allowance",
      "note": ""
    },
    {
      "id": "pcls-lsa",
      "area": "Pensions: allowances and tax-free cash",
      "title": "Tax-free lump sum from a £1,200,000 pot",
      "steps": [
        "A quarter of the pot: £1,200,000 × 25% = £300,000",
        "Capped by the £268,275 Lump Sum Allowance",
        "Tax-free cash £268,275"
      ],
      "workedByHand": 268275,
      "engine": 268275,
      "difference": 0,
      "withinTolerance": true,
      "engineFigure": "Projection: tax-free lump sum taken at 60",
      "rule": "gov.uk: Tax when you get a pension: lump sum allowance",
      "ruleUrl": "https://www.gov.uk/tax-on-pension/tax-free",
      "note": ""
    },
    {
      "id": "db-commutation",
      "area": "Pensions: allowances and tax-free cash",
      "title": "Final-salary pension £20,000, lump sum asked for £100,000 at 12:1",
      "steps": [
        "Tax-free cash is at most 25% of (20 × remaining pension + lump sum)",
        "With lump L at 12:1 the pension left is £20,000 − L ÷ 12, so L ≤ 25% × (20 × (£20,000 − L ÷ 12) + L)",
        "L ≤ £100,000 ÷ (0.75 + 5 ÷ 12) = £85,714.29",
        "The £100,000 asked for is capped at £85,714.29; pension given up £7,142.86"
      ],
      "workedByHand": 85714.29,
      "engine": 85714.29,
      "difference": 0,
      "withinTolerance": true,
      "engineFigure": "Engine: dbPermittedLump / dbCommutedLump (as the projection applies them)",
      "rule": "HMRC Pensions Tax Manual: PCLS applicable amount (PTM063240)",
      "ruleUrl": "https://www.gov.uk/hmrc-internal-manuals/pensions-tax-manual/ptm063240",
      "note": ""
    },
    {
      "id": "db-within-limit",
      "area": "Pensions: allowances and tax-free cash",
      "title": "Final-salary pension £20,000, lump sum £60,000 at 12:1",
      "steps": [
        "Permitted maximum as above: £85,714.29",
        "£60,000 is within it and is paid in full; pension given up £60,000 ÷ 12 = £5,000, leaving £15,000"
      ],
      "workedByHand": 60000,
      "engine": 60000,
      "difference": 0,
      "withinTolerance": true,
      "engineFigure": "Engine: dbPermittedLump",
      "rule": "HMRC Pensions Tax Manual: PCLS applicable amount (PTM063240)",
      "ruleUrl": "https://www.gov.uk/hmrc-internal-manuals/pensions-tax-manual/ptm063240",
      "note": ""
    },
    {
      "id": "sp-full",
      "area": "State Pension",
      "title": "35 qualifying years",
      "steps": [
        "Full new State Pension £241.30 a week",
        "× 52 = £12,547.60 a year"
      ],
      "workedByHand": 12547.6,
      "engine": 12548,
      "difference": 0.4,
      "withinTolerance": true,
      "engineFigure": "Engine: resolveStatePensionAnnual",
      "rule": "gov.uk: The new State Pension",
      "ruleUrl": "https://www.gov.uk/new-state-pension",
      "note": "The engine holds the annual figure rounded to the pound (£12,548)."
    },
    {
      "id": "sp-20",
      "area": "State Pension",
      "title": "20 qualifying years (record from April 2016)",
      "steps": [
        "20 of the 35 years: £241.30 × 20 ÷ 35 = £137.89 a week (to the penny)",
        "× 52 = £7,170.28 a year"
      ],
      "workedByHand": 7170.28,
      "engine": 7170,
      "difference": -0.28,
      "withinTolerance": true,
      "engineFigure": "Engine: resolveStatePensionAnnual",
      "rule": "gov.uk: The new State Pension",
      "ruleUrl": "https://www.gov.uk/new-state-pension",
      "note": "Applies to a record that starts after April 2016; earlier records use the transitional starting amount, which the plan takes from your forecast if you enter it."
    },
    {
      "id": "sp-min",
      "area": "State Pension",
      "title": "9 qualifying years",
      "steps": [
        "At least 10 qualifying years are needed for any new State Pension",
        "Nothing is payable"
      ],
      "workedByHand": 0,
      "engine": 0,
      "difference": 0,
      "withinTolerance": true,
      "engineFigure": "Engine: resolveStatePensionAnnual",
      "rule": "gov.uk: The new State Pension",
      "ruleUrl": "https://www.gov.uk/new-state-pension",
      "note": ""
    },
    {
      "id": "sp-defer",
      "area": "State Pension",
      "title": "Full State Pension deferred 52 weeks",
      "steps": [
        "gov.uk's example: deferring 52 weeks adds £13.99 a week (5.8% of £241.30)",
        "£241.30 + £13.99 = £255.29 a week",
        "× 52 = £13,275.08 a year"
      ],
      "workedByHand": 13275.08,
      "engine": 13276,
      "difference": 0.92,
      "withinTolerance": true,
      "engineFigure": "Engine: resolveStatePensionAnnual",
      "rule": "gov.uk: Delay (defer) your State Pension",
      "ruleUrl": "https://www.gov.uk/deferring-state-pension",
      "note": "The rule is 1% for every 9 weeks, which is just under 5.8% a year (5.78%, £13.94 a week); gov.uk's example and the plan's editable default both use 5.8%."
    },
    {
      "id": "annuity-65",
      "area": "Annuity",
      "title": "£200,000 pot at 65, level, single life",
      "steps": [
        "Published market-average rate at 65 for a level, single-life annuity with no guarantee: 7.1%",
        "£200,000 × 7.1% = £14,200 a year"
      ],
      "workedByHand": 14200,
      "engine": 14200,
      "difference": 0,
      "withinTolerance": true,
      "engineFigure": "Engine: calcAnnuity",
      "rule": "Hundred Summers Methodology: annuity rates (published assumption)",
      "ruleUrl": "https://hundredsummers.co.uk/methodology.html",
      "note": "Annuity rates are a published assumption, not a rule: this case checks the plan applies the rate it publishes. A real quote replaces it."
    },
    {
      "id": "iht-800k",
      "area": "Inheritance tax",
      "title": "Estate £800,000, home left to children",
      "steps": [
        "Nil-rate band £325,000 and residence nil-rate band £175,000 (home worth £400,000)",
        "£800,000 − £325,000 − £175,000 = £300,000 taxable",
        "£300,000 at 40% = £120,000"
      ],
      "workedByHand": 120000,
      "engine": 120000,
      "difference": 0,
      "withinTolerance": true,
      "engineFigure": "Engine: calcIHT",
      "rule": "gov.uk: How Inheritance Tax works: thresholds",
      "ruleUrl": "https://www.gov.uk/inheritance-tax",
      "note": ""
    },
    {
      "id": "iht-couple",
      "area": "Inheritance tax",
      "title": "Second death, £1,600,000 estate, both bands transferred",
      "steps": [
        "Nil-rate bands £325,000 × 2 = £650,000",
        "Residence bands £175,000 × 2 = £350,000 (home worth £600,000, left to children)",
        "£1,600,000 − £650,000 − £350,000 = £600,000 at 40% = £240,000"
      ],
      "workedByHand": 240000,
      "engine": 240000,
      "difference": 0,
      "withinTolerance": true,
      "engineFigure": "Engine: calcIHT",
      "rule": "gov.uk: How Inheritance Tax works: thresholds",
      "ruleUrl": "https://www.gov.uk/inheritance-tax",
      "note": ""
    },
    {
      "id": "iht-taper",
      "area": "Inheritance tax",
      "title": "Estate £2,200,000: residence band tapered",
      "steps": [
        "Residence band falls £1 for every £2 over £2,000,000: £175,000 − £100,000 = £75,000",
        "£2,200,000 − £325,000 − £75,000 = £1,800,000 at 40% = £720,000"
      ],
      "workedByHand": 720000,
      "engine": 720000,
      "difference": 0,
      "withinTolerance": true,
      "engineFigure": "Engine: calcIHT",
      "rule": "gov.uk: Inheritance Tax: residence nil rate band",
      "ruleUrl": "https://www.gov.uk/guidance/inheritance-tax-residence-nil-rate-band",
      "note": ""
    },
    {
      "id": "iht-taper-bpr",
      "area": "Inheritance tax",
      "title": "Estate £2,400,000 including £400,000 of business property",
      "steps": [
        "The taper looks at the estate BEFORE reliefs: £2,400,000 is £400,000 over £2,000,000, so the residence band tapers by £200,000, to nil",
        "Business relief at 100% (within the £2.5 million cap): £2,400,000 − £400,000 = £2,000,000",
        "£2,000,000 − £325,000 = £1,675,000 at 40% = £670,000"
      ],
      "workedByHand": 670000,
      "engine": 670000,
      "difference": 0,
      "withinTolerance": true,
      "engineFigure": "Engine: calcIHT",
      "rule": "gov.uk: Inheritance Tax: residence nil rate band",
      "ruleUrl": "https://www.gov.uk/guidance/inheritance-tax-residence-nil-rate-band",
      "note": ""
    },
    {
      "id": "iht-charity",
      "area": "Inheritance tax",
      "title": "HMRC's example: £750,000 estate, £50,000 to charity",
      "steps": [
        "Chargeable estate £750,000 − £50,000 = £700,000",
        "Baseline amount: £700,000 − £325,000 nil-rate band + £50,000 legacy = £425,000",
        "£50,000 is at least 10% of £425,000, so the 36% rate applies",
        "£700,000 − £325,000 = £375,000 at 36% = £135,000"
      ],
      "workedByHand": 135000,
      "engine": 135000,
      "difference": 0,
      "withinTolerance": true,
      "engineFigure": "Engine: calcIHT",
      "rule": "HMRC Inheritance Tax Manual: baseline amount (IHTM45009–45011)",
      "ruleUrl": "https://www.gov.uk/hmrc-internal-manuals/inheritance-tax-manual/ihtm45010",
      "note": "HMRC's own worked example (IHTM45010)."
    },
    {
      "id": "iht-charity-gift",
      "area": "Inheritance tax",
      "title": "HMRC's example: the same estate after a £150,000 gift four years earlier",
      "steps": [
        "The £150,000 gift (after the £3,000 annual exemption) uses £150,000 of the nil-rate band: £175,000 left",
        "Baseline amount: £700,000 − £175,000 + £50,000 = £575,000",
        "£50,000 is less than 10% (£57,500), so the rate stays 40%",
        "£700,000 − £175,000 = £525,000 at 40% = £210,000"
      ],
      "workedByHand": 210000,
      "engine": 210000,
      "difference": 0,
      "withinTolerance": true,
      "engineFigure": "Engine: calcIHT",
      "rule": "HMRC Inheritance Tax Manual: baseline amount (IHTM45009–45011)",
      "ruleUrl": "https://www.gov.uk/hmrc-internal-manuals/inheritance-tax-manual/ihtm45010",
      "note": "HMRC's own worked example (IHTM45011). The gift sits inside the nil-rate band, so it bears no tax and gets no taper relief."
    }
  ]
}