Martin Lewis has warned that millions will miss out on the £522 cash boost which parents on Universal Credit can get from today.
From today, (June 28) the amount parents on Universal Credit can claim back each month for childcare has risen by 47%.
This means parents can now claim back £951 for one child and £1,630 for two or more children - up from the previous rates of £646 for one child or £1,108 for two or more.
In an interview with Good Morning Britain today, the minister for children, families and wellbeing Claire Coutinho was asked by the Money Saving Expert why the help hadn't been extended to parents claiming Tax Credits.
Martin said: "There are still very substantial numbers of people who are still on legacy benefits and on the old tax credit system.
"The limits there, if we contrast it for one child, on Universal Credit you can claim up to £951 a month but if you're on the old legacy benefits system you can only claim up to £530 a month."
The minister told Martin that at the moment, the Government was working to transfer Tax Credit claimants onto Universal Credit.
She added: "I would say if someone is looking at these different schemes, they should go and talk to their job coach, go and talk to their DWP Jobcentre to see what's the right decision for them."
Those on Tax Credits get help with childcare costs through the childcare element of Working Tax Credit.
Like Martin said on Good Morning Britain, the maximum you can get for one child is up to £530 a month and for two children or more it's £910.
These amounts are significantly less than what people claiming Universal Credit will be getting from today.
Martin Lewis has previously urged Tax Credit claimants with children to check if they can switch to Universal Credit and then check if they can get childcare support.
A recent MSE newsletter said: "The Government estimates up to 1.4 million people (including some groups without children) would be better off switching from legacy benefits to Universal Credit (most will be switched regardless by the end of 2024, for a few it could be 2029 though)."
However, it also said people should "always" get one-to-one help with an approved charity like Turn2Us before applying to switch from legacy benefits to Universal Credit.
This is because some people actually may not end up being better off on Universal Credit - and once you have switched you can't go back.
