A 101-year-old Italian man who has been in London since 1966 was asked to get his parents to confirm his identity by the Home Office after he applied to stay in the country post-Brexit.

In what appears to be a computer glitch the Home Office thought he was a one-year-old child.

Giovanni Palmiero was told that he needed the presence of his mother and father when he made his application for the EU settlement scheme at an advice centre in Islington, north London.

When the volunteer who helped Palmiero, a great-grandfather, scanned his passport into the EU settled status app to share the biometric data with the Home Office, the system misinterpreted his birth year as 2019 instead of 1919.

Facebook Twitter Pinterest Giovanni Palmiero at the beach. Photograph: Giovanni Palmiero

“I immediately noticed that something was wrong because when I scanned in his passport, it imported his biometric data not as 1919 but as 2019. It then skipped the face recognition section which is what it does with under-12s,” said Dimitri Scarlato, an activist with the campaign group the3million who also works for Inca Cgil, an organisation that helps those of Italian descent.

He was then asked whether he wanted to put in the residence details of Palmiero’s parents or proceed independently of them. “I was surprised. I phoned the Home Office and it took two calls and a half an hour for them to understand it was the app’s fault not mine,” Scarlato said.

The Home Office then accepted the mistake and took Palmiero’s identity details over the phone. Last Thursday he was told he could resume his application as a 101-year-old.

He was then asked to provide proof of residence for five years in the country, even though he has been in the UK for 54 years and the Home Office is supposed to be able to access national insurance and tax records to corroborate five years of continuous tax residency.

Palmiero came to the UK in 1966 and “worked at a restaurant in Piccadilly and, up until the age of 94, in a fish and chip shop, until 11 o’clock at night”.

He has been married to his 92-year-old wife, Lucia, for 75 years and they have raised four children, and have eight grandchildren and 11 great-grandchildren.

His son Assuntino said: “It’s like a humiliation, you’ve been here so long and then all of a sudden this happens. I am not worried about him because he has got us but it’s completely unfair on old people.”

While the mistake seemed like a small computer bug, it was not a small mistake because the computer system “only recognised the last two digits of his year of birth”, Assuntino continued.

“It is more of a hassle than anything else. He is not going to be chucked out, but people of his age should not have to go through this process. They should just get it automatically. They should have a system for people who were here before 1973 and just post the documents out.

“They say you have to prove you have been here that long, but come on, they have HMRC records, council tax records. My parents are being sent their pensions, so how come they can’t find him on the system? If they wanted to check, they could easily.”

A Europhile, Palmiero was pleased when the UK entered the common market in 1973 but surprised by the result of the 2016 referendum.

“He always hoped that the UK would enter the common market and we were very surprised by this [Brexit],” his son said. “We have been assured by the consulate that we can always stay – he can’t return to Italy now as he has children and grandchildren here.”

Scarlato told the online newspaper Londra Italia the family had subsequently received an apology “for the inconvenience” from the Home Office. But they were still waiting for Palmiero’s settled status to be approved, according to Italian media reports.

The Home Office said it had been in touch with the centenarian and his application was being processed. “When Mr Palmiero’s case was raised our dedicated EU settlement scheme team contacted him and those supporting him to assist with his application,” it said.

It added that other applicants aged 100 or over have had successful settled status applications and 2.7 million people have been granted status since the scheme opened in March.