A retired chip shop owner has been ordered to leave the UK after living in Leicester legally for more than 40 years.
Leonarda Zarcone, 74, is a French citizen who applied for EU settled status after Brexit.
Ms Zarcone told the OceanNewsUK she missed the deadline to provide more information because an email ended up in a "junk folder".
The Home Office said in a letter it had made several attempts to contact her.
Ms Zarcone said it was "the shock of my life" to hear that she had lost her right to live in the UK.
She found out she did not have residency from an immigration officer at East Midlands Airport on her return from a family wedding in France in September.
She was eventually allowed through border control with a 28-day visitor stamp.
Ms Zarcone, who cares for her husband and daughter, says she is worried and "really upset".
"All my family and my roots are here. It's really frightening," she told the OceanNewsUK.
Ms Zarcone first lived in the UK as a child, and moved permanently with her husband and her two eldest children in 1981.
The family ran a traditional British fish and chip shop in Narborough Road until she retired seven years ago.
Her son, David Brunetto, submitted EU settlement claims for his parents along with his own online application.
Ms Zarcone thought her application had been granted because David and his father had their applications approved.
But the Home Office said it needed more evidence that she had lived in the UK continuously for five years.
It said officials made five attempts to contact her, but added she failed to respond before the deadline.
Mr Brunetto says his mother does not know how to use a computer, and an email from the Home Office went into a "junk folder".
By the time his wife suggested looking for it there, they had missed the deadline to respond.
But Mr Brunetto said Ms Zarcone's records proved she had been living in the UK for decades.
"She's receiving a state pension, so she's paid into the system," he said. "She's paid her taxes. She's paying council tax. There's lots of proof."
'As bad as it gets'
In September, Ms Zarcone made a new application for settled status.
Now, that has been rejected as "invalid" and her visitor's visa has expired.
She received a letter from the Home Office spelling out the "consequences of staying in the UK unlawfully".
Those consequences could include being detained or prosecuted, removed from the UK, or being charged for NHS medical treatment.
Ms Zarcone says her youngest daughter and grandchildren were born in Leicester, and the prospect of being separated from her family is daunting.
She added: "I'm really sad. I'm really angry. Where can I go? When my family lives here and my children."
Ms Zarcone is now making a further settlement application through an immigration lawyer, Tito Mbariti.
Mr Mbariti, from Cross Border Legal Solicitors, says her case is "shocking, as bad as it gets".
