No worries. We kinda decided to switch to fortnightly anyway to earn whatever compound interest we can on the payments, and hopefully not spend it! LOL.

But this is what the family assist site says:

What if I don't get fortnightly payments?

If you claim your Family Tax Benefit Part A as a lump sum at the end of the financial year, the payment will be made at the same time as your Family Tax Benefit Part A payment.

Please note: If you were eligible for Family Tax Benefit Part A on 14 October 2008 and you would like the payment earlier you can change to fortnightly payments.
So if I want it in December rather than when we do our tax returns, it seemed pretty clear I had to switch to fortnightly.

hmm.. I guess I shouldn't have said 'eligible' in my OP. I know we were eligible for the payment.. I just want it earlier

hmm... ok.. just re-read your post.. our estimates in the system were for last year which would indicate that we wouldn't be eligible for part A at all.. but my new estimates make us eligible.. so does that mean I still have to wait til tax time for the $2000? doh! Aah well.