2.4.6 The costs of the child
Context
The child support formulas (1.1.C.110) calculate the COTC to determine how the costs of each child in a child support assessment (1.1.C.70) will be shared by both parents (1.1.P.10) (either through care and/or the payment of child support (1.1.C.60)).
The COTC are calculated using the COTC Table. The current COTC Table (and previous 2 calendar years) can be found at 2.4.2, and historical tables are available at 2.4.13.
On this page
The COTC Table
The COTC Table is used to calculate the COTC for:
- children in relation to who a child support application can be made
- relevant dependent child (1.1.R.60) amount (2.4.4.25)
- multi-case child costs (1.1.M.50).
| Parents' combined child support income (1.1.C.190) or parent's child support income (1.1.C.120) | ||||||
|---|---|---|---|---|---|---|
| Fraction of MTAWE | 0 to 0.5 | 0.5 to 1 | 1 to 1.5 | 1.5 to 2 | 2 to 2.5 | Over 2.5 |
| Child support children | COTC | |||||
| All children aged 0 to 12 years | ||||||
| 1 child | 17% | 15% | 12% | 10% | 7% | - |
| 2 children | 24% | 23% | 20% | 18% | 10% | - |
| 3 children | 27% | 26% | 25% | 24% | 18% | - |
| All children aged 13+ years | ||||||
| 1 child | 23% | 22% | 12% | 10% | 9% | - |
| 2 children | 29% | 28% | 25% | 20% | 13% | - |
| 3 children | 32% | 31% | 30% | 29% | 20% | - |
| At least 1 child aged 0 to 12 years and 1 child aged 13+ years | ||||||
| 2 children | 26.5% | 25.5% | 22.5% | 19% | 11.5% | - |
| 3 children | 29.5% | 28.5% | 27.5% | 26.5% | 19% | - |
Act reference: CSA Act section 5 Interpretation—definitions, Schedule 1 The COTC Table
Ages of the children
The COTC Table is divided into:
- all children are aged 0 to 12 years
- all children are aged 13+ years, and
- children are of mixed age (the child support case (1.1.C.80) has children aged 0 to 12 years, and 13+ years).
The COTC for a day in a CSP (1.1.C.150) are calculated based on the age of the children on that day (CSA Act section 55G(4)). If a child turns 13 within the CSP the COTC will be calculated differently for the periods before and after the child's 13th birthday.
Example: Sam and Maria have 3 children, Alex aged 12, Nicholas aged 9 and Michael aged 8. The CSP starts on 6 September 2020. Alex's 13th birthday is on 12 November 2020.
The COTC are calculated using the COTC Table for 3 younger children (0 to 12 years) for the period 6 September to 11 November 2020. For the period 12 November 2020 to 5 December 2021 the costs are calculated using the mixed age amounts in the COTC Table.
Act reference: CSA Act Part 5 Division 6—The COTC
Number of children
The COTC Table determines the costs for up to 3 children in an assessment. Where there are 4 or more children, the costs are calculated for a 3 child family. When calculating costs for more than 3 children, the ages of the oldest 3 children are used (CSA Act section 55G(4)).
When there is more than one child in an assessment, the costs of each child is the total COTC divided by the number of children. This includes when there are children of mixed age, or where there are 4 or more children in the case.
Example: Ivan and Peta have 4 children, Adam aged 16, Deborah aged 15, Bristol aged 13 and Peta aged 8. The COTC are calculated using the ages of the 3 eldest children. As the 3 eldest children are aged 13 and over, the 'children aged 13+ years' section in the COTC Table is used. The costs of each child will be the total COTC divided by the actual number of children, which is 4.
Act reference: CSA Act Part 5 Division 6—The costs of the child
Income
The COTC Table is divided into columns that are a fraction of annualised MTAWE (1.1.A.50). The COTC are capped when combined child support income (or child support income) is greater than 2.5 times MTAWE.
Example: The parents' combined child support income is $210,000, for a CSP starting 6 April 2023. There are 2 children aged 13 and over. The COTC are capped at $47,451, the number in the last column of the '2 children' row in the table for older children (13+ years).
Parental income which may either be:
- combined child support income – for the COTC in formulas 1, 2, 3 and 4 (2.4.1),
- one parent's child support income
- multi-case costs,
- relevant dependent child amount,
- COTC using formulas 5 and 6.
Act reference: CSA Act section 46 Working out parent’s relevant dependent child amount, section 47 Working out multi-case allowances
COTC - the basic formula (1.1.B.10) method
The method used to work out the COTC using the COTC Table is:
| Step | Methodology | Example |
|---|---|---|
| Calculate the COTC | ||
| Step 1 – Child support income range | Locate the appropriate child support income bracket (column). | The parents' combined child support income is $86,000. |
| Step 2 – Number of children | Determine if there are 1, 2, 3 or more children and identify the correct row. If there is 4 or more children, identify the 3 oldest children. | There are 4 children aged 17, 15, 10 and 8. The 3 oldest children are aged 17, 15 and 10. |
| Step 3 – Ages of children | Identify the ages of the children - all under 13, all 13+ years or of mixed ages. Go to the corresponding range (box). | The 3 children are of mixed age – one child is aged under 13, and 2 children are aged 13+. |
| Step 4 – Calculate the COTC for the assessment (using 2023 values) | Follow the instructions in the box to determine the COTC. | COTC = $23,932 + (($86,000 − $82,525) × $0.275) = $23,932 + ($3,475 × $0.275) = $23,932 + $1,303 (rounded) = $24,888 |
| Calculate the COTC | ||
| Step 5 – Calculate the COTC for each child | Calculate the costs of each individual child by dividing Step 4 by the number of children in the assessment. | COTC = $24,888 ÷ 4 = $6,222 per child |
The amount calculated is rounded, to the nearest whole dollar (below 50c rounded down, 50c and above rounded up) at each step. This does not apply when calculating the rate of child support payable for a day.
Act reference: CSA Act section 55F Simplified outline, section 55G Working out the costs of the children, section 55H Working out the costs of the child, section 156 Rounding of amounts