Parents who have to be pursued through the courts or have child maintenance payments deducted from their wages will risk a charge of £300 under a new child support system that comes into force today.
Parents will also face fees if they cannot come to an amicable arrangement on supporting their children financially.
The new system means the Child Support Agency (CSA) will be phased out over the next three years and replaced with the Child Maintenance Service (CMS).
Letters have already been sent to 50,000 parents in England, Scotland and Wales earlier this year warning them of the changes.
More top news
Strong winds, heavy rain and snow forecast across the UK
Police are hunting a man suspected of trying to set Finsbury Park Mosque on fire earlier this morning
A company which specialises in electronic toys and educational material for children has revealed it has been the victim of a cyber attack.