Superannuation vs 401(k)
Both wrappers are employer-sponsored and tax-deferred. Australian super is mandatory (employer must contribute 11.5%); the US 401(k) is voluntary with employer match. Tax treatment also differs — super taxes contributions at 15%; the 401(k) defers all tax until withdrawal.
| Feature | SuperannuationAustralia — Mandatory employer-sponsored retirement | 401(k)United States — Voluntary employer-sponsored retirement |
|---|---|---|
Mandatory employer contribution | Yes — 11.5% of OTE (rising to 12% in 2026) | No — voluntary match |
Annual concessional / employee cap (2025/26) | AUD $30,000 | USD $23,500 |
Annual non-concessional / after-tax cap | AUD $120,000 (up to $360k via bring-forward) | After-tax 401(k) — plan-dependent, often $46,500 |
Tax on contributions | 15% inside super (30% if Div 293 applies) | Pre-tax — full deferral until withdrawal |
Tax on growth 401(k) is fully tax-deferred; super is "concessionally taxed". | 15% (10% on capital gains held >12mo) | |
Tax-free retirement phase Super tax-free post-retirement (up to $1.9m TBC); 401k always taxable. | Yes — once moved to retirement-phase pension | |
Earliest access age | Preservation age 60 (some still 55-59) | 59½ (with 10% penalty before, exceptions apply) |
Required minimum withdrawals | Yes — minimum drawdown rates by age | Yes — RMDs from age 73 |
Investment flexibility | Plan menu (industry/retail) or self-directed (SMSF) | Plan menu — usually 10-30 mutual funds |
Cross-border tax treatment | Complex — US/UK/Canada don't fully recognize super | Recognized under multiple treaties (Canada, UK, Australia) |
Mandatory vs voluntary — the structural divide
Australian Superannuation is mandatory. Every employer must pay 11.5% of Ordinary Time Earnings (OTE) into the employee's super fund — this is the Superannuation Guarantee. Rising to 12% on 1 July 2025. The employee can't opt out, and the contribution sits on top of salary rather than reducing take-home pay.
The US 401(k) is the opposite — voluntary, employee-funded via payroll deduction, with optional employer match. Most employers match 3-6% of salary if the employee contributes; some offer better matches or profit-sharing on top. There's no legal requirement that employers offer a 401(k) at all (and many small US employers don't).
This means an Australian employee accumulates retirement savings automatically at a guaranteed rate, while a US employee has to actively elect to participate and choose how much to contribute. The compliance + behavioural advantage is firmly with the Australian system.
Taxation: 15% in super, 0% in 401(k) (until withdrawal)
Super contributions and growth are taxed inside the wrapper at a concessional 15% rate (or 30% if Div 293 applies for high earners with combined income + concessional contributions over $250k). Capital gains on assets held over 12 months get a one-third discount, dropping the effective tax rate to 10%. Withdrawals in the retirement phase (post age 60, once the account is moved to "retirement phase") are completely tax-free up to the $1.9m Transfer Balance Cap.
The 401(k) defers all tax until withdrawal — contributions go in pre-tax, growth is untaxed, and the entire withdrawal is taxed as ordinary income at the time of withdrawal (whatever your marginal rate is then). There's no separate "retirement phase" — the wrapper just empties as you draw it down.
For long-time-horizon savers, the 401(k)'s deferral is more powerful in raw return terms — every dollar of tax saved compounds for decades. But super's tax-free retirement phase makes the after-retirement income side cleaner, and the mandatory contributions mean Australians often end up with larger absolute super balances than equivalent-earning Americans have in their 401(k)s.
Investment flexibility and the SMSF option
A standard Australian super account at an industry fund (AustralianSuper, REST, Cbus, Hostplus) or retail fund offers a curated menu of investment options — usually a balanced default plus a handful of alternatives. Fees are low, performance is decent, and most members never touch the default option.
For Australians who want full control, the Self-Managed Super Fund (SMSF) is an option. SMSFs are individually-controlled super funds where you manage the investments — buy individual stocks via CommSec, Stake, or IBKR; hold property; trade ETFs. Setup costs are higher (several thousand AUD annually for accounting + audit), so SMSFs are typically only economical with $500k+ in assets.
401(k)s are constrained to your employer's plan menu unless the plan offers a Self-Directed Brokerage Account, which is the exception not the norm. Most US savers route their stock-picking ambitions through their IRA or a non-registered account.
Frequently asked questions
Can I have both super and a 401(k)?
Yes if you've worked in both countries. A common pattern: Australian working in the US accumulates 401(k) while keeping their super back home (no new contributions while non-resident, but existing balance keeps growing). Cross-border tax treatment is messy — neither country fully recognizes the other's wrapper.
Which is better — super or 401(k)?
They serve different purposes. Super is mandatory and broad-based; 401(k) is voluntary but allows much higher employee contributions. As a single-country retirement vehicle, both work — the bigger question is whether your employer match is generous (401(k) wins if so) and how aggressive your concessional contributions are (super gets the 15% concessional tax instead of marginal).
Can I transfer super to a 401(k) if I move to the US?
No clean transfer mechanism exists. Super stays in Australia and continues to grow in the wrapper; you'd need to leave the country permanently to access it before preservation age (and even then, withdrawal triggers Australian tax). The 401(k) is established by your US employer — fund it for new retirement saving once US-resident.
Is super tax-free for US persons living in Australia?
Generally no — the IRS treats super as a foreign trust and may require Form 3520/3520-A reporting, plus growth inside the super wrapper may be taxable on the US side. PFIC rules can apply if super holds non-US mutual funds (most balanced super options do). Cross-border CPAs strongly recommend US persons in Australia minimize voluntary super contributions and prioritize Roth IRA / 401(k) instead.
Does WealthWatch track both?
Yes. SMSFs connect via brokerage (CommSec, Stake, IBKR Australia); industry / retail super funds use CSV import for half-yearly statements. 401(k)s connect via Plaid or supported account-aggregation. Concessional and non-concessional caps, 401(k) employee + employer limits, and Div 293 income flag all on the dashboard.