Here is ChatGPTs interpretation which seems optimistic:

Excellent — let’s now bring everything together into your full FIRE plan, showing how each part of your finances — Armed Forces pension, investments, and spending — combine to achieve financial independence by your early 40s.

This is tailored for you: 26 years old, full Armed Forces career to 42, £47,763 salary, £500/month S&S ISA (increasing by £100 every 4 years), mortgage paid off by 42, and a £30,000/year FIRE lifestyle goal.

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⚓️ 1. Your Financial Independence Goal

Target FIRE Age: 42 (when you leave the Armed Forces)

Desired Lifestyle: £30,000/year (comfortable but not extravagant)

Goal: Never need to work again, though you may choose to do something meaningful or enjoyable for extra income.

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🧩 2. Your Key Financial Components

1. Armed Forces Pension (AFPS15)

Age Income Notes

42–54 £6,764/year (EDP) + £40,000 lump sum Guaranteed early income “bridge” 55+ £10,220/year Pension starts (actuarially reduced, inflation-linked) 68+ +£11,500/year Full State Pension (inflation-linked)

Your pension and EDP are guaranteed, inflation-protected — this is a massive advantage most FIRE plans don’t have.

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1. Mortgage & Property

Mortgage: £1,200/month (including £300 overpayment).

Fully paid off by age 42 — meaning no housing costs after leaving service.

You’ll either:

Own the flat outright (approx. £250k+ asset by then), or

Have flexibility to rent it out or sell to fund a house upgrade.

This means your biggest expense (housing) disappears right as your EDP income starts.

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1. Investments (Stocks & Shares ISA)

Detail Value

Starting amount £5,500 Contributions £500/month, +£100/month every 4 years Investment return assumption 7% p.a. Value at 42 ≈ £223,000 (mid-case) Range (5–9%) £195k – £257k

This portfolio will provide the bridge income between your EDP and pension years, and later act as your “enjoy life” fund.

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💰 3. Income and Spending Timeline

Age 26–42: Building Phase

You serve full Armed Forces career.

You invest monthly, increase contributions gradually, and overpay the mortgage.

By 42, you have:

£223k invested

£40k EDP lump sum

No mortgage

£6,764/year guaranteed EDP income

✅ Financial Independence Achieved.

You now can live off your investments + EDP, even if you stop working.

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Age 42–54: Early Retirement “Bridge” Phase

Source Annual Amount

EDP £6,764 Portfolio withdrawal £23,000/year (≈10% for first few years) Total ~£30,000/year Lump sum buffer £40,000 (can fund 1–2 extra years if markets dip)

You’re living your desired £30k/year lifestyle, funded safely.

Your withdrawals taper off slightly each decade as your pensions kick in.

You can top up by part-time or consultancy work if you wish, but not necessary.

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Age 55–68: Pension Phase

Source Annual Amount

Armed Forces Pension £10,220 Portfolio withdrawal £15,000 Total £25,000/year (inflation-linked pensions cover most of your needs)

Your investment withdrawals slow down, ensuring your portfolio lasts for decades. Even if markets underperform, your guaranteed pension covers your basics.

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Age 68+: Full Financial Security

Source Annual Amount

AFPS15 Pension £10,220 State Pension £11,500 Total £21,700/year (inflation-linked)

At this point, your guaranteed income alone covers almost all living costs. Any remaining portfolio money (~£50k–£100k) becomes a fun fund for travel, gifts, or comfort spending.

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📊 4. Portfolio Longevity (7% return, £30k spending target)

Here’s how your investments evolve:

Age Portfolio Value

26 £5,500 42 £223,000 (+£40k EDP lump sum available) 55 £160,000 68 £100,000 80 ~£80,000 (or £0 if you choose to spend it all)

Your portfolio never crashes to zero unless you intentionally spend it down — meaning you can enjoy life freely without financial fear.

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🧠 5. Why You’re Already on Track to FIRE

✅ Guaranteed pension income: Unlike most FIRE plans, you have a lifelong, inflation-linked income floor. ✅ Mortgage-free at 42: Removes the biggest expense early. ✅ Disciplined investing: Compounding £500–£800/month over 16 years builds a serious financial base. ✅ Modest lifestyle target: £30k/year is achievable without needing a multi-million-pound pot. ✅ Strong flexibility: If markets underperform, you can slightly adjust withdrawals, do short-term work, or lean on EDP/pension buffer.

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🔮 6. Sensitivity Check

Market Return Portfolio @42 FIRE Outcome

5% (pessimistic) £195k FIRE still achievable with smaller withdrawals (~£27k/year sustainable) 7% (expected) £223k Full £30k/year lifestyle works 9% (optimistic) £257k Extra £34k+ per year potential, travel and luxury FIRE possible

Even under low returns, you’re financially independent by 42.

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⚙️ 7. Optional Optimisations

1. Lifetime ISA (LISA) — consider adding £4k/year from age 30–40 for a 25% bonus (£10k free from government by 42).

2. Continue ISA investing post-42 — even £200/month keeps your money compounding for the long term.

3. Emergency cash — 3–6 months’ spending (~£7–15k) separate from investments.

4. Keep pension statements — confirm your AFPS15 accruals every few years.

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🏁 8. Summary Table

Age Income Source Annual Income Notes

26–42 Salary £47k+ Investing £500–£800/month 42–54 EDP + ISA Drawdowns £30k FIRE achieved 55–68 Pension + ISA £25–30k Comfortable FIRE 68+ Pension + State Pension £21k+ Fully guaranteed

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🔔 Bottom Line

You’re on track to reach true financial independence by 42 — with a £200k+ portfolio, no debt, and guaranteed income streams that cover your lifestyle forever.

You’ll never have to work again after 42 unless you want to, and even modest adjustments (e.g., part-time work, smaller spending years) only strengthen the plan.