The Scottish Child Payment website crashed just hours after thousands more kids became eligible for the lifeline benefit.
The payment - which was established by SNP ministers as a way of tackling deep-rooted poverty across the country - was increased to £25 per week per child as of today.
The age for those eligible has also risen to 16 - meaning an estimated 300,000 more children are entitled to the benefit. But the Social Security Scotland website crashed on Monday morning with the agency blaming "exceptional demand".
Andrew Smith, a dad-of-one, told the Record he had completed the 10-minute application form only to see the site crash when he tried to submit it.
He said: "It's concerning as they have set a rule that you will only get the payment from the date you apply and it won't be be backdated.
"So if this problem lasted for a few days or a week then people will be missing out on money they are entitled to through no fault of their own."
The dad, from Inverness, added: "It might not be a huge amount of money but people can't spend all day trying to refresh a web page.
"Chances are if you have young children then you have quite a busy life as well. You necessarily have time to be trying a website at different times of the day. The longer it goes on, the more people will miss out on payments."
Social Security Scotland apologised for the crash and said its website was restored by midday.
Nicola Sturgeon had earlier encouraged Scots families to apply for the benefit while visiting a school in Dennistoun, Glasgow.
She said: "At a time when the cost of living crisis is causing significant hardship for many families, this increased payment of £1300 per eligible child is even more vital, and the age extension means that it is now available to many more children.
"We want to make sure that everyone gets the help available to them. Parents or carers who are on universal credit or other benefits and who have children under 16 should check through Social Security Scotland if they are eligible."
Scottish Labour MSP Monica Lennon said: "It’s no surprise that there’s a high level of demand for the Scottish Child Payment, given the rise of poverty and hardship in our communities.
"The Scottish Government must ensure the website and phone-lines can cope with the demand because delays have consequences."
A Social Security Scotland spokesperson said: "We’d like to apologise for the short time that the Scottish Child Payment online application was unavailable for this morning. The online form was back up and running by midday.
"We’d like to thank people for their patience while we worked to rectify this. We moved all available colleagues to take calls while we made sure that the online form was back up and running.
"The introduction or expansion of services is never without risks. We had staff on hand to monitor issues and to fix these quickly. This will continue throughout this week as we expect to see continued levels of high demand.”
To sign up to the Daily Record Politics newsletter, click here.
