Which account you draw from first changes the arithmetic

Most people reach retirement with money in several kinds of account rather than one. The order in which those are drawn is a decision, and leaving it unmade is also a decision.

Different accounts are not interchangeable

Accounts differ in how contributions were treated, how growth accumulates and what happens when money is taken out. Those differences persist into the drawing phase.

They also differ in access rules and in what happens to the balance on death. Two accounts holding identical investments can behave very differently once withdrawals begin.

The specific treatments vary by jurisdiction and are revised regularly, so the relevant rules are the current local ones rather than anything that can be generalised.

Sequencing changes how long the total lasts

Drawing from one account allows another to continue accumulating undisturbed. Which one is left alone therefore affects the total across a long retirement.

The effect is not small over decades, and it arises purely from ordering. Nothing about the underlying investments or the amount withdrawn has to change.

Because the effect comes from compounding, decisions made in the first years of drawing matter more than adjustments made later.

The plan interacts with income from elsewhere

State provision, workplace pensions and any continuing earnings arrive on their own schedules. Withdrawals fill the gap between those and required spending.

That gap is not constant. It is largest before other income sources begin and narrows as they start, which means the draw on invested money varies by year.

A sequencing plan built against average spending misses this. The years before other income begins are where the heaviest withdrawals fall.

Flexibility has a value that is easy to spend

Accounts that can be drawn freely are useful for meeting irregular costs. Exhausting them early removes that flexibility for the remainder of a retirement.

Retaining some ability to vary where money comes from is worth something in itself, particularly when circumstances change in ways nobody planned for.

That argues against following any sequencing rule mechanically to depletion, and in favour of leaving a reserve in the most accessible account type.

This is a question for a professional

Withdrawal sequencing depends on rules that vary by country, change over time, and interact with an individual's other circumstances in ways general description cannot capture.

It is one of the clearest cases in personal finance where the right answer is specific to the person, and where a general rule is likely to be wrong for most people applying it.

What is worth doing without advice is listing the accounts, their access rules and their balances. That list is the input any adviser would need first anyway.