EU citizens will lose their rights to live and work in the UK and to claim benefits if they miss the deadline.
But, do Irish citizens need to apply for settled status? Here’s what you need to know.
When did the UK leave the EU?
It has now been five years since the UK voted to leave the European Union in the Brexit referendum.
After a number of delays and extensions, the UK left the European Union at 11pm on 31 January 2020.
The country was then in a transition period until 31 December 2020.
EU citizens living in the UK need to apply with settled status to be able to stay in the UK under post-Brexit rules.
What is settled status?
Under the terms of Britain's departure from the European Union, EU citizens and their families no longer have an automatic right to live and work in the UK,as freedom of movement has come to an end.
EU citizens living in the UK have until the end of the day today (June 30), to apply to stay in the UK or lose their rights, under post-Brexit rules introduced by the government.
Settled status is available to anyone who can prove that they had been in the UK continuously for five years or more before 31 December 2020.
How many applications have been received, and how many people have already been granted settled status?
The most recent data shows that, as of 31 May, settled status has been granted to 2.75 million people.
More than 5.6 million applications have also been received for settlement status, but around 400,000 cases are still waiting to be processed.
Ministers say anyone who applies by the end of today will have their existing rights protected while their case is heard.
Do Irish citizens need to apply for settled status?
If you are an Irish citizen and you want to continue living in the UK, you do not need to apply to the EU Settlement Scheme.
The rights of Irish people to live, work and access public services in the UK are protected under the Common Travel Area arrangement.
However, even though Irish people do not need to apply to the scheme themselves, if they have foreign family members from outside of the UK and Ireland will need to apply.
How do I apply for settled status, and what happens once it has been granted?
To apply for EU settled status, you must visit the government’s website.
Once you’ve been granted settled status, you can: continue to use the NHS, study and access public funds and benefits, and travel in and out of the country freely.
What happens if I miss the deadline?
Anyone requiring settled status who misses the deadline will technically become an illegal immigrant overnight and may face a number of problems.
Without settled status, it’s illegal to work in the UK or receive benefits.
People living illegally in the UK must also pay to receive healthcare on the NHS.
The government has, however, promised a "pragmatic and flexible" approach to late applications.
It has said that anyone who has received a certificate proving they have applied will have their legal rights protected while officials process their paperwork.
The Home Office has also said that the scheme remains "indefinitely" open to people, but only if they can show they had reasonable grounds for missing the June 30 deadline.