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
The singer ended speculation over who would perform by saying "the rumors are true" to her 63 million Twitter followers on Friday morning.
There will be lighter winds for all of us than yesterday, although it will still feel cool.
Senior fashion analyst at Mintel Tamara Sender said: "For the first time ever sales of trainers have overtaken high heels."