The FIRE Sequence Problem: What Order Should You Draw Down Accounts?

Why drawdown order matters

Two FIRE retirees with identical portfolios and identical spending can have wildly different long-run outcomes purely based on which accounts they draw from in which order. The math has two compounding effects:

1. Tax efficiency on withdrawal. Different account types are taxed differently on withdrawal. Drawing from the right account in any given year minimises lifetime tax bill.

2. Preserved compounding. Accounts with the longest tax deferral and highest growth potential should be drawn from last, so they keep compounding while easier-to-access accounts get spent first.

Done well, optimal drawdown sequencing extends portfolio life by 5–10 years versus a naive equal-drawdown approach. The leverage is large enough to be worth genuine effort.

The general principle

A rough universal rule: spend the most-taxed money first while preserving the most-sheltered money last. The intuition:

• Money in a taxable account is being taxed on dividends and gains every year. Draining it removes ongoing tax drag.
• Money in a Roth/ISA is sheltered indefinitely. Leaving it untouched means it keeps compounding tax-free.
• Money in a Traditional 401k/SIPP is sheltered during accumulation but taxed on withdrawal. Drawing from it strategically (during low-income years) minimises lifetime tax.

The order this implies, simplified:

1. Taxable / GIA first
2. Roth / ISA in middle years
3. Traditional / SIPP last (or via conversion ladder)

Reality is more complex because tax bands matter and access-age constraints intrude. But the principle gives you the starting framework.

The UK drawdown sequence

For a UK FIRE planner with the standard wrapper mix, retiring at 45:

Years 45–54 (pre-SIPP access):

• Primary source: ISA (tax-free, accessible)
• Secondary source: GIA (manage to stay within £3k CGT exemption + £500 dividend allowance)

Years 55–66 (post-SIPP access, pre-state pension):

• Take 25% SIPP tax-free lump sum if useful (often to top up ISA bridge)
• Draw SIPP up to personal allowance (£12,570) tax-free annually
• Supplement from ISA if needed for higher spending
• Continue draining GIA opportunistically

Years 67+:

• State pension covers ~£12,000/year
• SIPP continues providing taxable income up to higher-rate threshold
• ISA covers anything above that

The key UK insight: the personal allowance is a free £12,570 of tax-free SIPP withdrawal every year from age 55. Don't waste it. If you have any pension money at all, draw at least £12,570/year from it to use the allowance, even if you don't need the income (you can re-invest into an ISA).

For deeper coverage of which wrapper to fund during accumulation, see our ISA vs SIPP article.

The US drawdown sequence

For a US FIRE planner retiring at 45:

Years 45–49 (pre-Roth ladder access):

• Primary source: taxable brokerage
• Plan: have 5+ years of expenses here so the conversion ladder has time to fill

Years 50–59 (Roth conversion ladder phase):

• Drain taxable brokerage for current spending
• Convert ~$25,000–40,000/year of Traditional → Roth at low marginal rates
• Manage realised income to stay in ACA subsidy band if relevant (typically ~$60k for couple)
• Withdraw Roth principal (original contributions + converted principal that's >5 years old)

Years 60–66 (full Roth/Traditional access):

• Continue Roth/Traditional balancing for tax efficiency
• HSA withdrawals if needed (for medical or, post-65, anything)

Years 67+:

• Social Security adds ~$30k–45k/year of guaranteed income
• Optimise Traditional withdrawals to stay below Social Security taxation thresholds where possible

The US insight: the Roth conversion ladder lets you access Traditional 401k money pre-59½ at the cost of just 5 years of patience and minimal tax. See our Roth/401k article for the mechanics.

When pure order isn't optimal

The "drain X completely, then Y" approach is conceptually clean but often tax-inefficient. Better practice usually involves mixing accounts each year to optimise marginal tax bands.

Example for a UK retiree at age 60:

• Pure order: spend £40k from ISA, leave SIPP untouched. Pay £0 income tax this year.
• Mixed approach: spend £12,570 from SIPP (free, uses personal allowance) + £27,430 from ISA. Pay £0 income tax. Preserve £12,570 of ISA for later years.

The mixed approach achieves the same spending, the same current-year tax, but ends up with more accessible ISA capital later. The mixed approach is strictly better.

Similar logic applies in the US. Mixing Roth and Traditional withdrawals each year to fill specific tax brackets typically beats pure-order drawdown by 5–15% of lifetime tax bill.

Planning backwards from terminal year

A useful practical exercise: assume you'll live to 90. Work out what you want your account balances to look like at 90 (typically: zero, or some bequest amount). Then work backwards through the decades to figure out what each account needs to support in each phase.

For UK planners retiring at 45 with 45 years of life expectancy:

• Final 5 years (age 85–90): SIPP slowly draws down, state pension continues, ISA mostly intact for late-life liquidity needs
• Late retirement (age 75–85): SIPP supports most spending; ISA buffer
• Mid retirement (age 67–75): state pension + SIPP cover most spending; ISA preserved
• Early retirement (age 55–67): SIPP + ISA bridge to state pension
• FIRE bridge (age 45–55): ISA-heavy, supplemented by any GIA

Working backwards makes the bridge requirements concrete. For a 12-year bridge from 45 to 57 at £30,000/year, you need at least £360,000 of accessible non-SIPP funds at the FIRE date. That sets your ISA accumulation target.

The tools-led approach

The right drawdown order depends so heavily on individual circumstances (tax band, spending pattern, asset allocation, state pension timing) that any single article can only give principles. The actual numbers should come from simulation.

Test different drawdown sequences in our simulator — toggle drawdown rules and watch how the survival curve responds. The optimal sequence for your specific situation often differs from generic advice by 1–3 years of additional plan longevity.