NSW Penalties for late re-payment instalments

[JazKaz]

loophole

Loophole, unlikely, covid-19 circumstances, more likely.

As for not paying, it is pretty terrible, but...

You’re entitled to a reasonable interest charge to offset your losses in having to wait, so long as that is already a part of your contract - or they agree to it in the negotiation of the deferred payment terms

Perhaps you could just keep sending them invoices, calculate the interest accrued and send them the info continuously and request that they make payments. That might be a fight back strategy to induce them to pay, if not no harm no fowl, less costly than court but it is likely that is where this will lead if you want the amount back...