Parents say they can not afford to send their children to school or pay off their mortgage because of problems they are having with the new tax credit system.
Angry readers have deluged BBC News Online with gripes about the new system, following an article on Tuesday highlighting the experiences of one reader Ted Duggan.
Worst affected appear to be those people who received the old-style credits - the Working Families Tax Credit and Disabled Person's Tax Credit - and who have not yet received a payment under the new system.
Amanda from England, a single parent, says she is worried she could be forced to leave work, as she won't be able to pay for childcare costs of £95 a week.
She is also concerned she may not be able to keep up with her mortgage payments.
"Two years ago they helped me get back to work. Now I feel I may be in a worse situation as I have bought my own house and do not want to give up my job," she writes.
Diana Adkins, a school science technician, needs help with credits to bring up her two children.
"I have been receiving very efficiently 'low income family tax credit' for the last three years...in fact it doubles my wages as a school science technician...meaning that I can support myself and my two children.
"I applied for the new credits in October, and have heard nothing."
Meanwhile, Emma McLear from Scotland, says she cannot send her child to nursery school.
"I have not even got food in the house and I don't have a family, so I don't know what to do in respect of my work or anything.
"This is like a nightmare."
One of the biggest problems for readers has been getting through on the helpline.
"I have for weeks been trying to get through on the helpline. I haven't managed to speak to one single person yet. I have tried on and off all day today from 7.30am till 6.30pm and never managed to get further than "you're call cannot be taken at the moment, please try later," writes one reader.
The Revenue has said it is putting an extra 700 staff in place to help alleviate the problems.
It won't come soon enough for David Mayer, who applied in January.
He was receiving Working Families' Tax Credit, but he hasn't received his award notice yet. Nor can he get through to the helpline.
Even when people have received notifications some are still awaiting payments.
Garry Qualter from Devon says he applied online last year, and a letter followed acknowledging the claim and how much he would receive.
"I have four children to raise on a low income. My award (£140 per week) is crucial. If payments are not sent out soon this whole mess will be disastrous for us.
Problems with the helpline
Non-processed claim forms
People who have received notifications, but have been sent new claim forms, as if they have not submitted a claim
Backlog in processing forms
Non-payment of awards
Computer system has difficulty processing double-barrelled names
" I have a feeling this mess will soon become much worse, as more families' finances reach the point where the bank refuse to pay direct debits and cheques."
Even when people have sent in their forms, some have been sent new claim forms.
Tim says he applied back in October 2002, and received acknowledgement that month.
But last weekend he got a set of new forms in the post.
"The whole system is a joke, why change it in the first place, they have reduced my Tax Code so I get £42 a month less, then get me to fill out a load of forms to give me £42 a month back it's a joke," he says.
The Treasury said in a statement it was confident that all payments will be made over the next two weeks.
In a statement, it said: "The Inland Revenue have already made over one million payments to those who requested weekly payments.
"And the two-thirds of all claimants who requested monthly payments are not due their money yet - they will receive their credits by the beginning of May as planned."
Local tax offices could arrange emergency payments if families do not receive the money they're owed, it said, as an interim measure.
I too applied for Tax Credits in December and heard nothing back until last week when I got a new claim booklet through the post. Since then have been trying to contact them from 7:30 - 6pm and i must say that it is really dissapointing and upsetting.
Linzi Martin, Scotland
They sent me a form stating my and my wife's earnings were significantly less than they were and awarding me too much credit. If I had left this unchallenged I would be in debt to the government to quite some degree and so I sent it back immediately 3 months ago for re-evaluation to avoid overpayment and now have not heard a thing. What would they rather a nation in rising debt to the governent because of administrative incompetence! This they will have no doubt. Debt surely is something the government is meant to solve not create.
Andy Phillips, England
We didn't apply until February. Towards the end of March I was telephoned at work by the IR, to say they were just about to start processing the form, and we would be notified mid-April. No problems yet, and I have been able to speak to someone on the help desk twice!
Applied online in October. Heard nothing at all since. Been trying to get through on the telephone for the last 4 weeks - just get a recorded message saying don't worry - all is fine.
I am yet to be convinced that all really is well.
We applied in November to receive weekly tax credits I have neither recieved any notification or any money. I can't get through to the Help Desk at all and when I rang the Inland Revenue they said there was no problem with the phone line at all!
I did not apply until late March. On Monday I received three cheques in the post for seemingly random amounts. I do not know whether these cheques are for outstanding child benefit owed to me, my tax rebates or this tax credit. There was no accompanying letter of explanation. I have failed to get through to the help line - apart from once when I was told that they could not tell me what the cheques were for or look me up due to the Data Protection Act!! I then phoned IR enquiries line and the man told me he did not know how I could find out and that no one could look me up. It is nice to get the money - but we also need to know where we stand and if we can expect more next week or next month...
I applied back in the autumn and had a letter saying I would be advised in due course of my award. On 2nd April I rang and was advised my claim was in progress and I would have a letter by the 9th. On the 9th I had a standard letter with a form inviting me to apply again. I spent two days trying to get through to the help line to confirm my previous claim was still in effect. I was told it would be but the system was down so they couldn't give me details. I asked to be called back and was told I would receive a call in 48 hours. You've guessed it that call has never come. Most of my colleagues and friends have applied and are still waiting to hear something, we are becoming convinced there is no intention to actually pay anyone anything. I shall wait a couple of weeks for some further info and if none comes I shall wite again - to my M.P.
I have a choice to either pay my childminder to keep working or to pay my rent to keep my house. Without paying one I risk the other. I cannot get hold of anyone on the telephone. I presume that the payments will be backdated.
It has gotten to the point that I am thinking of asking my boss to fire me. I must say the the Tax Credit I have received over the last couple of years was excellent and you could always talk to someone human! But this has made things a whole lot worse.
I have applied last year as soon as the first forms were sent out. Despite numerous calls to the "helpline?" no one was ever able tell us the amount of the award. Finally yesterday the award notice arrived and surprise surprise, the calculation is wrong for the amount paid for childcare has been disregarded!! Two full days of both wife and I trying the helpline again and when we finally got through.......the IT system is down, please call back later! We are a family with two young children and are on a medium low income, despite this the award is only £ 42,00 month. I will loose much more on my salary because of the change in tax code. Under the present calculations we are therefore better off if my wife stops working and starts claiming more benefits. I think this Tax Credit has turned out to be yet another big blunder and can do nothing but express anger and frustration on how the services in charge are treating taxpayers.