The life in the UK test certificate (so the unique reference number you get) does not expire except that the government has in the past committed to replacing the Life in the UK test with a new ‘British values test’. So it is possible that you take the Life in the UK test, but then the legislation changes. This would mean that you would need to take the new British values test. You would then likely not be able to rely on your the Life in the UK test certificate, unless there is some kind of transitional provision.
What is the probability of the Life in the UK test being replaced, and when will it be replaced? Well, the government was quite clear and unambiguous, in stating:
“Citizenship should mean more than being able to win a pub quiz. We need to make it a British values test – and that’s exactly what I will bring in.”
That was Sajid Javid speaking. This announcement was back in 2018, and it has not been implemented yet. But when you are asking: “How long is the Life in the UK test valid for?”, or “When does the life in the UK test expire?” then bear in mind that the government has strongly criticised the existing test, and said that it will be replaced. We don’t know when, but it is reasonable to assume that this would be before the end of the current government’s term in office, or the next if they win the next election. So although the Life in the UK test is technically unlimited, the reality is that it may not be valid indefinitely. It is likely to expire (in the sense that you will no longer be able to rely on your unique reference number), if the government introduces the new British values test. So once you take the Life in the UK test, it would be prudent to complete the process of applying for indefinite leave to remain within a reasonable time, or for citizenship depending on what stage you are at.
The reason the government wants to end the Life in the UK test is that it quizzes people on history, traditions and everyday life. The government believes it is based too much on facts, and not enough on values.
The current Life in the UK test is tricky and fact-heavy. Do check out my free course on YouTube. Many hundreds of people have used it to successfully pass.