New Zealand Law
Have New Zealand Law Questions? Ask a Lawyer Online.
You don't mention whether you have been through the formal objection process as yet. There is a form which you can use to object although they do try and make you pay until the objection is completed. If you need time to make payments you need to explain to them why you cannot pay the full amount at once.
From the IRD website, with links you can use
How to object to a decision or assessment
If you want to object to a decision or assessment, you can write to us telling us why you don't agree or complete a Notice of objection - child support (IR119) form.
We must receive the objection within 28 days from the date of the assessment. If you pay child support you must continue paying until the issue is resolved.
What happens after we receive an objection
After we receive an objection we'll review our decision or assessment and the reasons you've given in your letter or objection form, and let you know the outcome.
But unfortunately child-support is one of those items where there is no limitation period. The Child Support Act is specifically excluded from other usual limitation periods. To me one of your stronger arguments would be that you have changed your position relying upon the assessments being correct. But because child-support is a statutory obligation rather than a contract, this may not operate as a defence to the claim, but may help you get time to pay this at a rate which you can afford