Isaac 6: clearer, faster, and built for real life

Isaac 6 is the biggest update since launch. There’s a fresh look on every screen, a new “What would it take?” tool, proper support if you’ve already retired, better planning as a couple, Plan history, a redesigned App Lock and layouts built for tablets and desktops. Your existing plans carry straight over.

Released 29 September 2026 · iOS, Android & web

We rebuilt a lot of Isaac this summer. Not to add clutter, but to make the answers clearer and quicker to reach. Here’s what’s new, what’s changed, and what (if anything) you need to do.

A fresh look, everywhere

Every screen now uses one set of colours, type, spacing and shapes, with the DM Sans typeface and a deep navy dark mode. It sounds cosmetic. It isn’t: when every screen works the same way, you spend less time working out the app and more time looking at your plan.

The pot chart shows your money in purple while it builds and blue once you start drawing on it, with dashed lines for the optimistic and cautious cases. Markers along the top show the moments that shape your plan, such as your State Pension starting, your partner retiring, selling a home or a big cost. The income breakdown uses clearer colours, with the net and gross switch on the left and your drawdown order just below it.

“What would it take?”

This is the one we’re most excited about. Pick a question and Isaac works out the answer from your own plan:

• When could I retire? The earliest age the model shows your money lasting.
• How much could I spend? The monthly spending your money could support.
• What would I need to save? The monthly saving your plan would need.

Choose the age you want the money to last to (85, 90, 95 or 100), and Isaac holds everything else in your plan steady. If the answer looks good, save it as a new scenario with one tap. Your current plan stays exactly as it is. It’s free for everyone.

The Retirement Year Planner

The year you stop work is the most complicated tax year most people ever have. Salary for part of it, perhaps a final bonus or redundancy pay, then tax-free cash, a pension withdrawal or two, and maybe your State Pension starting part way through. Get the order wrong and you can pay 40% on money that could have been taxed at 20%, or nothing at all.

The new Retirement Year Planner works that year out to the day. Enter your last day of work, your pay (or the figures from your final payslip), any final or redundancy pay, the tax-free cash and withdrawals you’re thinking about, and any other income. Isaac then shows you:

• The tax for the whole year, and whether payroll has probably taken too much, so some could come back.
• How your income fills the tax bands, and how much more could come out at 0% or before the 40% line.
• Emergency tax on a first withdrawal: roughly how much a provider might take at first, and the form to reclaim it.
• Your choices side by side, each run through your whole plan, so you can see the tax this year, the tax over your retirement and how long your money lasts.

Your State Pension and any final salary pension are counted from the exact day each starts, and the first £30,000 of redundancy pay is kept tax-free. When you’re happy, one tap puts the year into your plan so every other screen uses it. It’s a Premium tool, and like everything in Isaac it’s a guide rather than advice: it links straight to Pension Wise and to finding a regulated adviser.

Tax-efficient drawdown

The page that sets which of your pensions and savings are used first has been rebuilt and renamed, because tax is what it’s really about. Each order now shows how long your money lasts, how much is drawn and the tax paid, side by side. An order that pays less tax simply because the money runs out sooner is no longer shown as a win.

Already retired? Isaac now starts from today

Plenty of you are already retired, and Isaac used to make you think like someone who isn’t. Not any more. Setup asks whether you’ve already retired and whether you already get your State Pension, then skips the retirement age and contribution questions entirely.

From there, every screen treats you, your partner or both of you as retired. Pensions that are already being paid appear on your timeline from today, rather than on dates in the past. What if, “What would it take?” and the full-screen chart only show the controls that still apply to you.

Planning as a couple, without the guesswork

Partner Link has had a lot of attention. Your partner’s own pensions and savings count in your joint figures, their plans carry their name, and every screen shows whose plan you’re looking at and who last changed it. Changes reach the other device within about 20 seconds.

If you both edit the same plan at the same time, Isaac tells you, and neither version is lost: the other one is kept in Plan history. You can also choose to be notified when your partner updates a plan. Your partner can join for free.

Simpler spending

Spending is now one monthly amount, with changes for later in retirement if you expect to spend more or less as time goes on. Not sure where to start? Tap one of the PLSA Retirement Living Standards benchmarks. If you already have a plan, it keeps exactly the same spending; nothing is lost in the switch.

The stress test: one answer, then what to do about it

Monte Carlo is now the Stress test, and it opens with one number: the chance your money lasts to the age you choose, across 1,000 simulated futures. Returns vary around the growth rates in your own plan, inflation varies from year to year too, and the same plan gives the same answer every time you open it.

Under the answer sits why: the band of outcomes year by year, the chance you are still alive at each age, and how the plan would have fared had you retired in every year on record, hardest year first. Then the levers. Depending on the verdict, Isaac offers the changes that would make the plan more secure, or shows how much room you have to spend more or retire earlier, and tests each one on the same 1,000 futures so the comparison is fair. You can also choose how each pot is invested as you age and test that too. The guide to the stress test explains how to read it.

Plan history, App Lock and your data

• Plan history brings back a plan deleted in the last 30 days, or a version your partner saved over, as a new copy you can open straight away.
• App Lock has been redesigned, with a Forgot PIN? option, a limit on wrong guesses, locking again when you come back after five minutes away, and Change PIN in Account. Turning the lock off now needs your PIN, Face ID or fingerprint.
• Hide screen when switching apps covers your figures in the app switcher.

Proper layouts for every screen

Isaac now has proper layouts for iPad, foldables, landscape and desktop web, rather than a stretched phone screen. On larger screens your inputs sit beside live results that update as you type, so you can see what each change does without flicking between tabs. Money fields add thousands separators as you type, and the forms are grouped into short, clearly headed sections.

Up to date with the rules

The calculations follow current legislation:

• Income tax thresholds stay frozen until April 2031, and savings income is taxed at the 2027/28 rates.
• Scottish tax bands, the cash ISA limit from April 2027 and tax on non-ISA investments are now modelled.
• The triple lock guides cover the plan announced in September 2026 to change it from 2030.
• A new Rules and sources page lists the legislation and official figures behind every calculation.

Because the thresholds now stay frozen for longer, some plans will show slightly more tax in later years than before. That’s the law catching up with the projection, not a mistake.

What’s gone

The dashboard’s Earliest Retirement Age and Scenarios sections have been retired. “What would it take?” answers the first question better, and you can switch scenarios from the header on any tab.

Free and Premium

Building your plan is free: every pension type, property, savings, the spending curve, your partner’s details, the projection and income charts, “What would it take?”, Excel export and cloud sync. Premium adds the tools that stress-test and explain your plan: the Retirement Year Planner, Monte Carlo, What if, scenarios side by side, year-by-year detail, the PDF report, Chronology, Pots view, tax-efficient drawdown, inheritance tax planning and partner linking.

Premium is £7.99 a month or £79.99 a year. New to Isaac? You can try Premium free for 3 days when you set up your plan, with no payment taken.

See your own plan in Isaac 6. It takes about five minutes to set up.

or use Isaac on the web →

Thank you to everyone in the Good Ideas Club who told us what to build and what to fix. A lot of this update came straight from you. Keep it coming.