Most EU citizens settled in the UK will retain their rights to live and work in the country after Brexit, but on January 1 a two-tiered system comes into force that may exclude thousands.
The right of EU citizens to move to and settle in Britain without a visa will cease to exist on January 1, when Britain no longer has to abide by the bloc's rules.
EU citizens who have been living in the UK for less than five years have to apply for pre-settled residency status to allow them to live, study and work as well as claim healthcare and benefits.
Those who have lived in the country for more than five years can apply for settled status, which gives recipients the right to stay indefinitely.
Romeo Manciu, 39, arrived from Romania before Brexit and secured pre-settled status, as did his wife, daughter and father who joined him later.
"You just have to prove that you are in the UK, and this is very simple, for example with a bank statement," he told AFP.
"I included my father in my bank account and got him a credit card and insurance for his car. He can prove that he's in and that's enough," he added.
Poles (773,840) and Romanians (670,600) have made the highest number of applications for settled status, followed by Italians (401,800), Portuguese (306,350) and Spanish (246,600).
As of September 2020, 3.9 million applications have been processed with 56 percent granted settled status.
Forty two percent were granted pre-settled status and two percent of applications were withdrawn, rejected or found invalid.
More than a third of the 17,000 individuals rejected were from Romania, which has one of the lowest GDPs per capita among EU member states.
- Slip through the cracks -
One of the main arguments made by pro-Brexit campaigners before Britain's 2016 referendum was that leaving the EU would stop the arrival of migrants from poorer EU countries.
Manciu, who helps his compatriots who have little or no English, said some Romanians had experienced more difficulty settling in the UK.
"There are a lot of people who work in the black market and are not renting legally. Some also have criminal convictions," he said.
The immigration changes at the end of the Brexit transition period on December 31 also include a rejection of EU citizens who have been jailed for more than a year.
EU citizens -- as well as those from Iceland, Liechtenstein, Norway and Switzerland living in the EU -- have until June 30 2021 to apply for settled status.
But there are fears the changes could see the elderly in care homes, vulnerable children and other people who are difficult to contact or unaware of the deadline slip through the cracks.
Maike Bohn, from pro-EU campaign group the3million, said her friend's 82-year-old mother, who has Alzheimer's, is German but has lived in the UK so long she is assumed to be British.
"I try to tell her daughter that she has to ask for the status," otherwise her mother could lose her right to health care, she added.
Bohn said the difference for those who arrive after January 1 will be "dramatic" as they will require visas to work, study, rent a house or gain access to public health.
"They will be treated as third-country nationals," she added.
- Devil in the detail -
A new, stricter points-based immigration system will give preferential treatment to more qualified foreign workers.
"To obtain a visa you have to have a job first, and it has to be a skilled job, so with some education levels and paid in line with the market price," said the chief executive of the East European Resource Centre in London, Barbara Drozdowicz.
Luke Piper, an immigration lawyer, said key workers in areas like health, agriculture and the performing arts would be applying in "very restrictive circumstances".
That is despite earlier government promises to allow specific routes for immigration in these sectors.
"The devil is in the detail," he added.