Most retirement plans get judged on one question. Can you afford it?

In a recent Globe and Mail Financial Facelift column, a Toronto couple named Mandy and Syed got a clear yes. Their planner, Corrinna Paxton of Objective Financial Partners in Kelowna, B.C., tested their plan at a conservative 4% return over 30 years and concluded that Mandy can retire in 2027.

But that question has a second half: in what order should you spend it? Two plans can fund exactly the same lifestyle and still pay very different amounts of tax over a lifetime.

So I took the figures published in the column and built two plans in Optiml. The planner's biggest call held up, and Optiml made the same call on its own. The withdrawal order by itself was worth $123,262 in lifetime tax.

Mandy and Syed, By the Numbers

Everything in this section comes straight from the column.

• Mandy, 64: business manager earning $126,000 a year. She wants to retire in 2027, and she has a defined benefit pension of $12,000 a year starting at 65.
• Syed, 65: part-time trainer earning $10,000 a year, planning to keep working part-time for another two or three years.
• Home: mortgage-free in Toronto, worth $1,300,000. No debt. Net worth of $3.1 million.
• Goal: $75,000 a year after tax, rising with inflation.

Their savings break down like this:

• Mandy's Registered Retirement Savings Plan (RRSP) and Locked-In Retirement Account (LIRA): $856,000
• Syed's RRSP/LIRA: $476,000
• Syed's non-registered account: $237,000
• Syed's Tax-Free Savings Account (TFSA): $145,000
• Mandy's TFSA: $108,000
• Cash: $19,800

Add it up and $1,332,000 of their roughly $1.84 million in savings sits in RRSPs and LIRAs. More than 70% of their investments are in accounts where every dollar withdrawn counts as taxable income.

When those dollars come out is what this case study is about.

What the Planner Recommended

• Yes, Mandy can retire in 2027.
• Delay the Canada Pension Plan (CPP) and Old Age Security (OAS) to 70.
• Convert the RRSP/LIRA before age 71.
• Preserve the TFSAs for as long as possible.

This is a sound plan. Deferring CPP to 70 raises the payment by 42% compared with starting at 65, and deferring OAS raises it by 36%. Both are indexed to inflation for life. Holding the TFSAs in reserve makes sense because TFSA withdrawals don't count as taxable income. And testing at 4% was a deliberately conservative choice.

I wanted to test one thing the recommendations leave open: the order in which the accounts get drawn down in the years before the benefits start.

How We Modelled It

I entered their exact figures into Optiml, built two plans and put them side by side in Compare Plans.

• Plan 1, Traditional: Optiml's standard, un-optimized deposit and withdrawal order. CPP and OAS start at 70, matching the planner's recommendation.
• Plan 2, Maximize After-Tax Estate: Optiml's strategy (called Max Value in the app) for leaving the largest possible after-tax estate without cutting the lifestyle. I gave it no instructions on CPP or OAS, so it could pick any start age.

Both plans had to fund the same $75,000 a year after tax, growing with inflation, for the entire plan.

Where the Advice Held Up

Mandy can retire in 2027. Both plans are successful, and both fund the full $75,000 lifestyle from start to finish.

Both also earned a Success Score of 96. That means the plan fully funded their lifestyle in 48 of the 50 market scenarios it was stress-tested against, which were drawn from more than 50,000 generated return paths. That's a resilient plan whichever way you run it.

Then there's the biggest call. Optiml was free to start CPP and OAS at any age, and it chose 70 for both, the same answer the planner gave. For this couple, deferral isn't a rule of thumb. It's what the math picks when it has a free hand.

Where It Can Be Sharpened: The Withdrawal Order

Here's how the two plans compare.

The lifestyle, the benefit timing and the Success Score are all identical. The only thing that changed is which account each dollar came from, and when.

What Optiml Did Differently

• In 2026, while Mandy still earns $126,000: no registered withdrawals at all. Spending comes from non-registered savings and cash.
• From 2027, once her salary stops: Optiml draws the RRSPs down heavily, roughly 10% of the account each year, through the lower-income years before CPP and OAS begin at 70.

That is the biggest difference between the two plans. Optiml draws the registered accounts down earlier and more steadily. The Traditional plan holds off, then has to draw them down faster and in bigger amounts later.

Pulling from an RRSP while you're earning a $126,000 salary stacks taxable income on top of taxable income. So Optiml leaves the registered accounts alone in the highest-income year and waits for the paycheque to stop.

Why the Gap Years Matter

Look at the household's taxable income once Mandy retires. There's her $12,000 pension from 65 and Syed's $10,000 from part-time training for a couple more years. Nothing from CPP or OAS yet. For a household that was earning $136,000 the year before, that's a very low taxable income.

Low income usually sounds like a problem. In a drawdown plan it's an opening. Every RRSP dollar withdrawn in those years is taxed at lower rates than the same dollar would be later.

And later is where the Traditional plan runs into trouble. Its delayed withdrawals come later and bigger, including after the RRSPs are converted to a Registered Retirement Income Fund (RRIF). They land on top of CPP, OAS and Mandy's pension, so the same dollars get taxed at a higher marginal rate.

Stack enough income and you cross the OAS clawback threshold. For 2026 income it's $95,323 of individual net income, and OAS is reduced by 15% of every dollar above it. In the Traditional plan the clawback came to about $2,500 in total. That's small, but it tells you the income is landing in the wrong years. Optiml's order brought it to zero.

Why the Estate Grows Too

The $123,262 in tax that Plan 2 never pays doesn't disappear. It stays in the plan and stays invested. That's how the after-tax estate comes in $142,946 higher without Mandy and Syed spending a dollar less along the way.

It also shows why the strategy name matters. I didn't ask Optiml to minimize tax. I asked it to maximize what they leave behind after tax, with the lifestyle held fixed. Paying less lifetime tax is how it got there.

Run Your Own Version

Mandy and Syed's situation is common. Plenty of Canadian couples in their sixties have a large RRSP, a retirement date several years before 70 and a plan to defer CPP and OAS.

If that sounds like you, the question isn't whether to defer. It's what you live on until your benefits start.

You can answer that yourself. Build a Traditional plan and a Maximize After-Tax Estate plan in Optiml, open Compare Plans, and read the lifetime tax, OAS clawback and after-tax estate side by side. You can try it free for 14 days.

The Bottom Line

The planner got the big decisions right. Mandy can retire in 2027, and when Optiml was free to choose, it picked the same CPP and OAS age: 70.

The gain came from sequencing. If the RRSPs are drawn earlier and more steadily in the low-income years before the benefits begin, the same $75,000 lifestyle costs $123,262 less in tax and the OAS clawback disappears.

Retirement income isn't just about when your benefits start. It's about what you draw before they do.