Video report by ITV News Political Reporter Shehab Khan
Hundreds of EU citizens are reaching out to charities every day with concerns about their status in the UK, ITV News has learned.
The deadline to fill out this online application is June 30 but many are unaware that they need to.
Kate Smart, from the charity Settled, says there are a number of issues, ranging from having poor technology skills and being unable to fill the form out online, to those who were previously given a permanent residency document not knowing they also have to apply.
Kate Smart, chief executive of the charity Settled warns about those falling through the cracks of the system.
She said it was a "great achievement" that millions had gone through the system successfully but warned "something that is working at speed like this means there will be people who fall through the cracks."
"People who may be having trouble with their documents or people who are not very techy... may be finding it difficult."
She added: "There are people who feel exempt from this, who have got another status and they think that's safe and for some of those people that's not going to be safe."
The government will, as of today, be launching a new advertisement campaign to ensure that everyone who needs to apply is aware of it.
“Every day, thousands of people are being granted status under the hugely successful EU Settlement Scheme," Future Borders and Immigration Minister Kevin Foster said.
"So with just 30 days until the application deadline, I urge people who are eligible to apply as soon as possible, secure the rights they deserve in UK law and join the 4.9 million people who have already been granted status."
“The Government is committed to making sure everybody eligible for the scheme can apply, including those who are the most vulnerable or need extra support.
"We have made available up to £22 million in funding through to 30 September 2021 for a network of now 72 organisations across the UK.”
But there are worries that significant numbers could fall through the gap.
Lara Parizotto and her grandmother Adelia Fruet have lived in the UK for more than a decade.
Adelia isn’t particularly tech savvy, her English isn’t great and because she has worked as a cleaner who gets paid cash in hand, she is worried that she doesn’t have the necessary documents she needs to do the application.
Although her granddaughter is helping her through the process, she is worried about those who don’t have the extra support.
Lara Parizotto helped her grandmother through the process but says "it's a shame that we have to apply to stay in our home".
Lara told ITV News: "It's a shame that we have to apply to stay in our home.
"Firstly we didn't have a voice on the referendum, we didn't have a say and a lot of people were promised that nothing was going to change for EU citizens that had been lawfully resident in the UK and that has not been the reality of it.
"The reality is we have a lot of things we have to apply for, we have to prove our status, we have to prove our residence, we have to try to find documents here and there to make sure we're not going to lose our rights.
She added: "It just worries me so much that, even the tiniest percentage that don't apply, will be so negatively affected by it."
The government says it is committed to making sure everybody who is eligible for the scheme can apply, including those who are vulnerable or need extra support.