yup - i'm not sure what the ATO lump sum claim asks - but if it asks for an estimate of partner income, you'd be paid based on that (no wonder they won't do that anymore after this year - too confusing!) - then when DH does his return, you'll get the difference of what you've been underpaid (if you over estimated his income) and the supplements

IF however, you underestimated his income, you'd not get the full amount of the supplements as they'd use those to correct any over payment

and yes, you do get paid your 30% rebate in september

and even better, in October, they start paying the quarterly 50% rebates for child care!