 Some families are still waiting |
Tax credit claimants face losing a full year's payments unless they submit their forms by Monday 7 July.
Those eligible for child tax credits who have yet to put in their claims must ensure their forms are received by midnight on Monday.
From April 2003, the New Tax Credit replaced the old benefits and tax credits with a single system, but many people have not yet received the credits.
According to government figures, more than four million families are receiving the credits, while a further 220,000 are still having their claims processed.
Income boost
All families with children and an income up to �58,000 a year (or up to �66,000 a year if they have a child under one year old) are eligible to claim for the child element of the new tax credits.
Claims received after 7 July can still be backdated for up to three months, but claimants who submit their forms beyond this date will not be eligible for a full year's award.
This means people need to claim their credits as soon as they can.
Chas Roy-Chowdhury, Head of Taxation at ACCA, said: "Many families will be unaware that 7 July represents the cut-off date for them to receive the credits payments due for April-June this year.
"This is, however, understandable, given that information on the deadline date is sparse, even for those actively looking for it."
The Revenue suggests that people who have not already submitted a form should do so over the internet to ensure it gets there on time.
Existing claimants
While complaints about the service have fallen, some BBC News Online readers are still experiencing problems, particularly with the Inland Revenue's telephone helpline.
Giles Eldridge from Camden in north London says he has no idea what is going on with his claim, as he has been unable to contact advisers by phone.
It is a complete baffle  Giles Eldridge, tax credit claimant |
Mr Eldridge, who received the old-style Working Families Tax Credit, submitted his claim at the end of March, but has received no feedback from the Inland Revenue to date.
"It does seem to be a complete reversal of the old system, which was very easy to apply for, and was simply implemented," he said.
Monday deadline
The Conservatives plan to mark Monday's deadline with a debate on tax credits.
"We are very worried about millions of families who are losing out on the government's new tax credits," David Willetts, Shadow Work and Pensions spokesman, told BBC News Online.
"There are still several hundred thousands who have put in claims who have not received the benefit, and there are many more who haven't even put in a claim."
Both the Treasury and Revenue have apologised to people who have not yet received their money.
The Revenue told BBC News Online on Friday it was "doing everything possible to ensure people received their money".
Steve Webb, Liberal Democrat spokesman for work and pensions called on the government to ensure that payments for people who were on the old-style credits were prioritised.
"Those who were receiving WFTC and DPTC must be at the top of the pile," he said.