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Some services unavailable 16 - 17 November | myIR, gateway services and our self-service phone line will not be available from 3pm Saturday 16 November to 9am Sunday 17 November while we do planned system testing. This will not affect any tax entitlements or payments scheduled during this time.

You can estimate your income for child support when you expect it to be at least 15% less than the income used to work out your current child support assessment.

Before you start

You'll need:

  • your total income for the year so far (since 1 April), including any overseas income
  • what you think your income will be for the rest of the year (until 31 March).

Go to your child support panel in myIR

Then select 'More...'

Select 'Apply for a child support income estimation'

Fill in your details

Submit your estimation

Log in to myIR

You can fill out the Estimate of income for child support assessment – IR104 form online or on paper.

Check you've included your correct information and any documents we need. Sign the form and send your documents to us at:

Child Support
PO Box 39010
Wellington Mail Centre
Lower Hutt 5045

Child support - contact us

What happens next

If we accept your estimate, we'll reassess your child support and send you a new notice.

After the end of the tax year, we'll compare the income you estimated with what you actually earned. If necessary, we'll reassess your child support. 

If we cannot accept your estimate, we'll send you a letter explaining why.


My responsibilities

We may ask you for evidence to support your estimate. These could be payslips or a letter from your accountant or tax agent, for example.

If your estimate includes overseas income, you'll need to send us proof of the actual income you earned after the end of the New Zealand financial year (1 April to 31 March).


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Last updated: 08 Feb 2024
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