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2.4.9.10 Formula 3 - multiple child support cases

Context

Formula 3 is used to work out the annual rate (1.1.A.70) of child support (1.1.C.60) payable for a child when one or both of the parents (1.1.P.10) have at least one other case, and there is no non-parent carer.

Act reference: CSA Act section 7B-'eligible carer', section 36 Formula 2: Working out annual rates …, section 37 Formula 3: Method statement …, section 38 Formula 4: Working out annual rates …, section 41 Working out parent’s child support income, section 42 Working out parents’ combined child support income, section 46 Working out parent’s relevant dependent child amount, section 47 Working out multi case allowances, section 48 Simplified outline, section 55A to section 55E Working out other elements for the formulas, section 55HA Working out the costs of the child …, section 156 Rounding of amounts

Formula 3

StepActionMore detail
1

Follow steps 1 to 6 of Formula 1 – the basic formula (1.1.B.10)

  • Step 1 - Work out each parent's child support income (1.1.C.120)

    Where a parent has more than one child support case (1.1.C.80), their child support income needs to be calculated separately for each case, as the parent's ATI (1.1.A.20) and multi-case allowance (1.1.M.30) may differ across their child support cases.

  • Step 2 - Work out the parents' combined child support income (1.1.C.190)
  • Step 3 – Work out each parent’s income percentage (1.1.I.30)
  • Step 4 – Work out each parent’s percentage of care (1.1.P.70) for the child
  • Step 5 - Work out each parent’s cost percentage (1.1.C.200) for the child
  • Step 6 – Work out each parent’s child support percentage (1.1.C.140) for the child
2.4.7
1A

Work out the COTC (1.1.C.210) for the day, calculating the costs for older and younger children separately (section 55HA). This is the same approach to calculating multi-case child costs (1.1.M.50) but uses combined child support income (1.1.C.190).

  • Identify the costs for the child for that CSP (1.1.C.150), based on the combined child support income of the parents
  • Identify the number of children in the child support case
  • Identify the ages of the child support children
  • In respect of each child support child:
    • Assume that all the child support children are of the same age as that child, and
    • Identify the item in the relevant column in the COTC Table that covers the number of child support children of that age

The COTC are the costs identified in the COTC Table divided by the number of child support children

-
1BIf the parent has a positive child support percentage from Step 1, calculate how much child support is payable for that child2.4.7
2Work out each parent’s multi-case cap (1.1.M.40) (if any) for the child for the day (section 55E)-
3

If a parent has a positive child support percentage for a child, the annual rate of child support payable is the lower of:

  • Step 1B child support payable
  • Step 2 multi-case cap for the child (if any)
-

Example - Using 2024 rates

In case 1, Vincent (ATI of $50,000) and Faith (ATI of $35,000) have 2 children, Geraldine aged 14 and Thomas aged 10. In case 2, Vincent has one child, Honoria, aged 5. Vincent has regular care (1.1.R.50) of all the children, providing care for 75 nights a year. Neither parent has any relevant dependent children (1.1.R.60). Faith does not have any other child support cases.

Case 1 calculations

Step 1 – calculate child support income

 VincentFaith
ATI$50,000$35,000
Self-support amount (1.1.S.20)$28,463$28,463
Relevant dependent child amountNot applicableNot applicable
Multi-case costs / multi-case allowance
Geraldine aged 14

Child support income = $21,537 ($50,000 − $28,463)

COTC = $2,297

  • ($21,537 × 32% = $6,892)
  • $6,892 ÷ 3
Not applicable
Thomas aged 10

Child support income = $21,537 ($50,000 − $28,463)

COTC = $1,938

  • ($21,537 × 27% = $5,815)
  • $5,815 ÷ 3
Not applicable
Honoria aged 5

Child support income = $21,537 ($50,000 − $28,463)

COTC = $1,938

  • ($21,537 × 27% = $5,815)
  • $5,815 ÷ 3
Not applicable
Multi-case allowance$1,938 (Honoria’s multi-case cost)-
Child support income

$19,599

  • $50,000, less
  • $28,463, less
  • $1,938

$6,537

  • $35,000, less
  • $28,463

Step 2 and 3 of Formula 1 – combined child support income and income percentage

 VincentFaith
Step 2 – combined child support income$26,136 ($19,599 + $6,537)
Step 3 - calculate income percentage74.99%25.01%

Step 4 and 5 of Formula 1 – percentage of care and cost percentage

 VincentFaith
Step 4 – calculate percentage of care
Geraldine20% (75 ÷ 365 nights)80% (290 ÷ 365)
Thomas20% (75 ÷ 365 nights)80% (290 ÷ 365)
Step 5 - calculate cost percentage
Geraldine24%76%
Thomas24%76%

Step 6 – child support percentage of Formula 1

 VincentFaith
Geraldine50.99% (liable parent)−50.99%
Thomas50.99% (liable parent)−50.99%

Step 1A - work out COTC for the day under section 55HA
Calculate the child costs for each child.

Geraldine
  • Combined child support income = $26,136
  • Costs based on combined child support income = $7,579
  • Costs for the child = $3,790 ($7,579 ÷ 2 children in case)
Thomas
  • Combined child support income = $26,136
  • Costs based on combined child support income = $12,853
  • Costs for the child = $3,136 ($6,273 ÷ 2 children in case)

Step 1B - work out how much child support is payable for each child

Geraldine$1,933 ($3,790 × 50.99%)
Thomas$1,600 ($3,136 × 50.99%)

Step 2 - work out the multi-case cap (multi-case costs − (100% − cost percentage))

Geraldine$1,746 ($2,297 × (100% − 24%))
Thomas$1,473 ($1,938 × (100% − 24%))

Step 3 - calculate child support payable

Geraldine$1,746 (multi-case cap is less than child support $1,933)
Thomas$1,473 (multi-case cap is less than child support $1,600)
Total$3,219

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