Freelance TV and film sound editor Louise Burton is one of those who are unable to benefit from government pandemic support schemes, despite being out of work.
Louise, 28, of St Albans, in Hertfordshire, has not had a single penny of assistance since her last job ended eight months ago.
"With the last production that I was on, I was hired as a PAYE freelancer, which means that I essentially do exactly the same job as what I do as a freelancer, but I was paying tax at source," she told the BBC.
"What often happens with film is that production companies are made for the sole purpose of the film. So they create these companies and everything goes through the company - and then once the film is completed, they then shut the company."
That means Louise fell foul of tax rules relating to self-employed people. And she could not go on furlough, because the company that had employed her no longer existed.
"I always feel guilty saying that I am one of the people who is suffering, because actually, I still have a roof over my head and I can just about put food on my table, but it's not easy," she says, adding that she fears for her prospects in the next 12 months.
According to MPs, whole groups of people like Louise are falling through the cracks of Covid-19 support schemes because of out-of-date tax systems.
Some freelancers and self-employed people have been particularly excluded, despite lockdowns and restrictions meaning they cannot work, the Public Accounts Committee said.
Others, meanwhile, are able to abuse the system, it said.
The government said its "top priority" was helping those who are struggling.
Since March, HM Revenue and Customs has provided more than £80bn in support to companies and individuals through government coronavirus support schemes, the committee said.
They are also supporting the incomes of many of the self-employed.
But despite this, a report from the MPs says "quirks in the tax system" have meant that groups of workers - including freelancers and self-employed people who recently moved onto company payrolls or work on a series of short-term employment contracts with gaps in between - have been ineligible for furlough payments.
"As public spending balloons to unprecedented levels in response to the pandemic, out-of-date tax systems are one of the barriers to getting help to a significant number of struggling taxpayers who should be entitled to support," said MP Meg Hillier, chair of the Public Accounts Committee (PAC).
By contrast, she said some large companies that had used government support schemes had continued to pay dividends to shareholders and high salaries to executives.
She added that HMRC was in many cases failing "to capture or deal with those wrongly claiming" support.
The tax agency should explain to freelancers and other groups why they have been excluded from receiving support and set out steps to fix the problem within six weeks, the MPs said.
The PAC also said that a lack of certainty about government coronavirus support schemes had made it difficult for businesses to plan effectively.
For example, HMRC could not provide clarity on whether the Job Retention Bonus scheme had been delayed or scrapped, the committee said.
The scheme was meant to pay employers an incentive for every worker they brought back from furlough and kept in employment until January.
"Such lack of clarity may lead to unnecessary hardships for some businesses, who in good faith were relying on the payments from the scheme to meet some of their needs," the MPs said.
A government spokesperson said it had done "all it can to help as many people as possible".
"HMRC delivered Covid-19 support schemes at unprecedented speed, protecting the livelihoods of millions of people.
"We do not underestimate the challenges faced by individuals and businesses during the pandemic, and our top priority is getting financial support to those struggling... while protecting the taxpayer against fraud.
"Those not eligible for support through these schemes can still benefit from the strengthened welfare safety net, accessing help like universal credit."