Spouse Super Contribution Calculator AU 2025-26

What this calculator works out

Australia gives married and de facto couples two distinct ways to use the super system as a couple, both administered by the ATO under the Income Tax Assessment Act and SIS regulations:

• Mode 1 — Spouse contribution tax offset. A non-refundable tax offset of up to $540 for the contributing spouse who pays $3,000 of after-tax money into a low-income spouse's super fund.
• Mode 2 — Contribution splitting. Transfer up to 85% of your previous-year concessional contributions (employer SG + salary sacrifice + personal deductible) to your spouse's super after the financial year ends.

This calculator handles both modes for FY 2025-26 with current ATO thresholds. Sources: ATO — Spouse super contributions, ATO — Contributions splitting, and ATO — Concessional contributions cap.

The formula and where the rates come from

Mode 1: Spouse contribution tax offset (s 159T ITAA 1936):

offset = 18% × min(
           $3,000,                        // base cap
           contributionAmount,            // actual after-tax contribution
           max(0, $40,000 - spouseIncome) // taper component (cap reduces from $37k)
         )

maximum offset = 18% × $3,000 = $540

The "spouse income" here = spouse's assessable income + reportable fringe benefits + reportable employer super contributions, not just taxable income.

Mode 2: Contribution splitting (SIS Reg 6.44):

maxSplittable = min(
                  0.85 × concessionalContributionsPrevYear,  // 85% rule
                  $30,000                                    // FY 2025-26 cap
                )

The 15% reduction reflects the contributions tax already paid by the receiving fund — splitting cannot move money that has not yet been taxed.

Eligibility quick-check:

Test	Mode 1 (offset)	Mode 2 (split)
Spouse age limit	< 75	< 65 (or 60-64 not retired)
Living together	Required	Not required
Spouse income limit	< $40,000	None
Spouse Total Super Balance	< $1.9M	No specific limit
Goes against spouse's non-concessional cap	Yes	No
Application	Make the contribution by 30 June	Lodge ATO form NAT 15237 with fund AFTER 30 June

How to read the inputs

Mode 1 (Offset):

• Contribution to spouse super — after-tax money you transfer to your spouse's super fund. BPay or EFT, with their member number. Anything over $3,000 doesn't increase the offset (but still counts toward the spouse's non-concessional cap).
• Spouse's assessable income + RFB + RESC — assessable income + reportable fringe benefits + reportable employer super contributions. NOT just taxable income. Includes salary sacrifice super.
• Spouse age — must be under 75 at the time of contribution (you can still contribute up to 28 days after the month they turn 75).
• Living together — married or de facto, including same-sex couples. Separated under one roof = NOT eligible.

Mode 2 (Split):

• Previous-year concessional contributions — employer SG + salary sacrifice + personal deductible contributions (where you claimed a tax deduction by lodging an NoI). Not non-concessional.
• Desired split % — anything from 0% to 85%. Typically you split the maximum to equalise balances.
• Spouse age — must be under 65, or aged 60-64 and not retired (not having met a condition of release on grounds of retirement).

Worked examples

1. Maximum $540 offset. Sarah contributes $3,000 to husband Tim's super. Tim earned $25,000 (part-time) plus no RFB or RESC. Offset = 18% × min($3,000, $3,000, $40,000 - $25,000 = $15,000) = 18% × $3,000 = $540. Sarah claims this on her tax return as a non-refundable offset. Tim's super grows by $3,000.

2. Income taper — partial offset. Sarah contributes $3,000 to Tim. Tim's spouse income = $38,500 (closer to the upper threshold). Cap = max(0, $40,000 - $38,500) = $1,500. Counted contribution = min($3,000, $1,500) = $1,500. Offset = 18% × $1,500 = $270. Contributing more than $1,500 wouldn't increase the offset at this income level.

3. Above the threshold — zero offset. Sarah contributes $3,000 to Tim. Tim's spouse income = $42,000 (full-time low-skill role). Cap = max(0, $40,000 - $42,000) = $0. Offset = $0. The $3,000 still goes into Tim's super (counts toward his $120,000 non-concessional cap), but Sarah gets no tax benefit.

4. Smaller contribution. Sarah contributes $1,000 to Tim (income $20,000). Offset = 18% × min($3,000, $1,000, $20,000) = 18% × $1,000 = $180. To unlock the full $540, contributing $3,000 would have been required.

5. Contribution splitting — typical case. James earned $90,000 last year and made $13,500 of concessional contributions (11.5% × $90,000 SG + $3,150 salary sacrifice). After 1 July, he lodges ATO NAT 15237 to split 85% to wife Priya's super: $13,500 × 85% = $11,475 transferred from James's account to Priya's. Useful because Priya is 5 years younger and they want to equalise balances ahead of the $1.9M Transfer Balance Cap.

6. Splitting with high concessional contributions. Tony made $40,000 of concessional contributions last year (using carry-forward unused cap from prior years). 85% × $40,000 = $34,000, but capped at the FY 2025-26 cap of $30,000 maximum split. The leftover $10,000 stays in Tony's account.

7. Combined strategy. Couple where one earns $130k and the other $20k (parental leave). Higher earner contributes $3,000 to spouse super → $540 offset. Higher earner also splits 85% of their $25,000 concessional contributions = $21,250 → spouse's balance grows by $24,250 in the year. Useful for pre-retirement balance equalisation in a single-income year.

Common pitfalls

• Spouse income includes RFB and RESC. Many people enter only taxable income and overestimate the offset. Salary sacrifice super counts as RESC and pushes the figure up. Check the spouse's PAYG payment summary line "Reportable employer super contributions".
• The contribution must be after-tax (non-concessional). Salary-sacrificing into your spouse's super is NOT how this works — you sacrifice into your own super, then split (Mode 2) or make a separate after-tax contribution (Mode 1).
• Counts against spouse's non-concessional cap. A $3,000 spouse contribution uses $3,000 of the receiving spouse's $120,000/year non-concessional cap. Usually fine, but if the spouse has already triggered bring-forward or is approaching the $1.9M Total Super Balance, this can cause excess contributions.
• Splitting is annual, after EOFY only. You cannot split a contribution made today. Wait until after 30 June, then lodge NAT 15237 with your fund for the previous year's contributions. Some funds have shorter internal deadlines (e.g. 30 September).
• Not all funds offer splitting. Industry funds typically do; some retail funds and SMSFs may have restrictions. Check before relying on it as a strategy.
• Spouse age 65 limit for splitting. Splitting requires the receiving spouse to be under 65, OR aged 60-64 and not retired. If your spouse retires at 62, you can no longer split to them.
• Splitting doesn't change your concessional cap. A $20,000 split still counts $20,000 against YOUR cap, not the spouse's. Splitting moves money already inside super, not new contributions.
• No offset for de facto separations. "Living together" is strict — separated under one roof or living apart for work doesn't qualify, even if still legally married.

Related calculators

• Salary Sacrifice Super Calculator — calculate concessional contributions you could later split.
• Super Co-Contribution Calculator (AU) — government co-contribution for low-income earners (different scheme).
• Super Carry-Forward Cap Calculator — use unused concessional cap from previous years.
• Super Non-Concessional Cap Calculator — check headroom before making a spouse contribution.
• Division 293 Extra Super Tax Calculator — high-income super tax that can be reduced by splitting.

Sources:

• ATO — Spouse super contributions
• ATO — Contributions splitting
• ATO — Concessional contributions cap
• ATO — Total Super Balance
• Income Tax Assessment Act 1936 — s 159T
• Superannuation Industry (Supervision) Regulations — Reg 6.44 (splitting)