About 800 EU citizens have been granted the right to remain in the UK using a system intended for those affected by the Windrush scandal.
Many are using it because of a lack of trust in the government's main EU settlement scheme, which MPs have said is "blighted" by technical issues.
Unlike the Windrush scheme, it does not provide a physical ID card showing a person's indefinite right to stay.
The Home Office said it gives people "secure digital status".
It added that the settlement scheme "protects the rights of EU citizens in UK law".
'Jumped through hoops'
The Windrush scheme was set up after individuals arriving from Commonwealth countries between 1948 and 1971 were wrongly told they were in the UK illegally, despite living in the country for decades.
But the application system is open to anyone who arrived, or whose parents arrived, before 1989.
Individuals are invited to a post office to provide fingerprints and an electronic signature, and would then receive a biometric ID card.
Daniela Fudge Condon - whose mother came to Bradford from Italy in the 1950s to work in the textile mills - said she feared that, without physical documentation, EU citizens could be treated in the same "horrific" way as the Windrush generation if the government's purely digital system went wrong.
In May, MPs also warned a similar scandal could take place with EU citizens if "serious concerns" were not put right.
Ms Fudge Condon's mother was successful in her application, but she argues it was unfair the 82-year-old had to apply at all.
"My mum's already jumped through hoops and gone through an immigration system back in the 50s. She shouldn't have to do that again," she told BBC Two's Victoria Derbyshire programme.
Currently, EU nationals - and their families - living in the UK by 31 October have until the end of 2020 to apply to the EU settlement scheme in the event of a no-deal Brexit, or the end of June 2021 if there is a deal.
Home Office estimates suggest more than a million individuals - fewer than a third of those eligible - have been granted settled or pre-settled status so far.
Dominique Zaccari - who arrived from Paris in 1973 and went on to establish an English language school in Bournemouth with her husband Antonio - also used the Windrush scheme to ensure she had physical documentation.
She said she received her ID card within a month of applying.
She admitted to feeling "terribly guilty about getting it off the back of the suffering of the Windrush people", but added that ultimately it was about "obtaining a document which I felt was due, because we've been here this long".
The Home Office said: "Applying to the EU settlement scheme is quick and easy, and over a million people have been granted status so far in the first few months since fully launching.
"It protects the rights of EU citizens in UK law and gives them a secure digital status which, unlike a physical document, cannot be lost, stolen or tampered with.
"There is plenty of support available if people need help, and they have until at least December 2020 to apply."