FIRE glossary
401(k) Equivalent (Workplace Pension / SIPP)
A 401(k) is a US employer-sponsored retirement account that gets tax relief on the way in and is taxed as income on the way out — most other countries have some version of that same trade-off, just built differently and under a different name.
What a 401(k) actually does
A 401(k) is a retirement account offered through a US employer. Money going in is typically deducted before income tax, sometimes matched in part by the employer, and left to grow inside the account without tax drag year to year. Tax comes due later, when money is withdrawn, at that point taxed as ordinary income rather than as a capital gain. That shape — relief on contributions, tax on withdrawal, growth untouched in between — is the design pattern worth understanding, because it's the pattern most other countries' equivalents also follow, even where the details diverge sharply.
The UK equivalents: workplace pension and SIPP
The UK's closest counterparts are a workplace pension, arranged and often part-funded by an employer, and a SIPP (self-invested personal pension), which anyone can open independently of their job. Both follow the same broad shape as a 401(k) — contributions get tax relief, growth inside the wrapper isn't taxed year to year, and withdrawals are taxed as income — but the UK versions add a feature the 401(k) doesn't have: a portion of the pot can usually be taken as a tax-free lump sum once you're old enough to start drawing it, rather than every pound out being taxed as income.
Elsewhere: EU pillars, Australian super, and the UAE gap
Most EU countries build retirement saving around a multi-pillar system: a state-run pay-as-you-go pillar, an occupational or employer pillar, and often a voluntary private pillar that most resembles a 401(k) or SIPP in mechanics — though contribution rules, access ages and tax treatment vary meaningfully by country. Australia's compulsory superannuation guarantee is a closer structural cousin again — employer contributions into a locked-until-preservation-age account — though it isn't itemised in Ember's engine today. The UAE, by contrast, has no domestic income tax and no equivalent tax-advantaged retirement wrapper at all for most residents; anyone building a pot there is typically doing it through a taxable brokerage account or an employer-offered scheme rather than a government-sanctioned wrapper, which is a genuinely different starting point, not just a smaller version of the same idea.
Why "equivalent" is doing a lot of work
None of these are interchangeable with a 401(k) — they're the closest functional match in each jurisdiction, built independently under different tax law, with their own access ages, lump-sum rules and contribution mechanics. Reading this page as "the UK/EU/AU version of a 401(k)" is a useful mental shortcut for understanding the trade-off; reading it as "identical rules under a different name" will get the details wrong. Check the specific rules for your own country before relying on any of this for a real decision.
Across borders
A 401(k) doesn't travel: leave the US and the account stays put under US tax rules, while your new home almost always has its own wrapper, with no automatic conversion between the two. The reverse holds for Ember's own users too — a UK workplace pension held by someone who moves to the US, the UAE or anywhere else keeps its UK source and its own treaty-routed tax treatment, rather than becoming a 401(k) by relocation. Ember's engine tags each pension or investable pot with its own tax wrapper and, separately, the country whose rules apply to it — a UK SIPP held by a UAE resident stays identified as a UK SIPP for that routing, never silently reclassified as a different wrapper type. See /countries for how each covered jurisdiction's pension and tax rules are actually modelled.
Common questions
Is a UK SIPP exactly the same as a 401(k)?
No — similar trade-off (tax relief in, income tax out), different mechanics. A SIPP is self-directed and not tied to an employer, has different access-age rules, and a portion can usually be taken as a tax-free lump sum at the point you start drawing it — a feature the 401(k) doesn't have in the same form. Treat "equivalent" as functionally similar, not identical.
What if I've worked in the US and then moved somewhere with no 401(k)-style wrapper at all?
The 401(k) itself doesn't convert into anything — it stays a US account under US rules, and you'd typically manage it as a separate US-taxed pot alongside whatever wrapper (or lack of one) your new country of residence offers, rather than expecting one to fold into the other.
Does Ember model every country's version of this?
Not itemised one by one. Ember's engine has explicit wrapper types for the UK (ISA, LISA, SIPP) and the US (401k, Roth IRA, traditional IRA), a UAE-resident type for the no-wrapper case, and a generic tax-deferred "pension" wrapper for other countries' schemes — see /countries for what's modelled where.
Related terms
See 401(k) equivalent (workplace pension / sipp) in your numbers
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