The offset is 18% of the lesser of your contribution and $3,000, reduced by $1 for every $1 your spouse earns above $37,000 – nothing at $40,000. Your spouse must be under 75 and their non-concessional contributions within the cap.
FAQ
What is the maximum spouse contribution tax offset?
$540 – 18% of a $3,000 contribution when your spouse earns $37,000 or less.
Sources (checked 6 November 2026): Income Tax Assessment Act 1997 s. 290-230; ATO, Spouse contributions tax offset.