Calculator

Arrears Calculator

Calculate your total maintenance arrears with a full month-by-month breakdown. Add any partial payments received to get the precise outstanding balance.

Enter maintenance details

Enter the weekly maintenance amount and the period you want to calculate arrears for. Then add any payments that were made.

Weekly maintenance amount (£)

As set by the CMS in your calculation notice

Arrears start

Arrears end

Payments received (optional)

Add any partial or full payments made during this period

No payments added — arrears will be calculated as if no payments were received.

How this calculator works

Enter the weekly maintenance amount set by the CMS
Select the period — from when payments should have started to today
Optionally add any payments that were actually made
The calculator shows a month-by-month table and the total outstanding balance

Use this for evidence

The arrears breakdown can help when contacting the CMS, writing a complaint letter, or preparing evidence for a tribunal. Always verify the figures with the CMS — their records are the official reference.

Enforcing arrears

If you are owed arrears, the CMS has a range of enforcement powers including:

–Deduction from earnings orders
–Deduction orders from bank accounts
–Liability orders (leading to bailiff action)
–Disqualification from driving or passport
–Commitment to prison (last resort)