However, the Bank of England has since suggested that the downturn might already be over.
Prime Minister Rishi Sunak said growing the economy was one of his five key priorities.
How do you measure the health of the economy?
The Office for National Statistics (ONS) publishes figures for the UKʼs Gross Domestic Product (GDP). This is the value of all the goods and services the UK produces.
In normal times, a countryʼs economy grows, GDP rises, and average incomes rise as a result.
But sometimes the economy shrinks, GDP falls, and thatʼs a sign that the economy is doing badly, which could hit peopleʼs pockets.
What is GDP and how does it affect me?
What is a recession?
The UK is in recession if GDP falls for two successive three-month periods - known as quarters.
The latest ONS figures confirm that the economy shrank 0.3% between October and December 2023.
That followed a 0.1% fall between July and September and means the economy went into recession at the end of 2023.
Across 2023 as a whole, the UK economy grew by 0.1%.
The government has never publicly said what measure should be used to assess the prime ministerʼs pledge to "grow the economy", despite repeated requests.
In private briefings, journalists were told it would be met if the economy was bigger in the fourth quarter of 2023 than in the previous quarter. The ONS figures show that it was not.
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When was the last UK recession and how long did it last?
The last UK recession was in 2020, at the height of the coronavirus pandemic.
It only lasted for six months, although the 20.4% fall in GDP recorded between April and June 2020 was the largest on record.
The previous recession started in 2008 as a result of the global financial crisis, and went on for five quarters, or 15 months.
What happens in a recession and how does it affect me?
Economic growth can mean more jobs are available and companies can pay more to employees and shareholders.
Higher wages and larger profits also generate money for the government through taxes.
It can choose to spend more on things like benefits and public services, or cut tax rates.
When the economy shrinks and a country goes into recession, these things can go into reverse.
Some people might lose their jobs, and unemployment could rise. Graduates and school leavers could find it difficult to get their first job.
Others may find it harder to be promoted, or to get big enough pay rises to keep pace with price increases.
However, the pain of a recession is typically not felt equally across society, and inequality can increase.
Benefit recipients and those on fixed incomes are particularly likely to struggle, especially if the government decides to spend less on public services.
How can you get out of a recession?
In a recession, the Bank of England - which is independent of government - typically cuts interest rates.
This makes it cheaper for businesses and households to borrow money which can boost spending and economic growth.
However, prices have been rising very quickly in the UK, and the Bank put interest rates up to tackle that inflation.
After 14 rate increases, the Bank has held interest rates at 5.25% four times in a row.
When the economy is struggling to grow at the same time as there is high inflation, there can be a situation called "stagflation".
This can be very difficult to solve, because the two issues require different solutions.
However in February 2024, Bank of England governor Andrew Bailey told MPs that there were "distinct signs of an upturn" in the economy and the latest recession may already be over.
How does the UKʼs economy compare with other countries?
The UK has been one of the weaker members of the G7 group of the worldʼs largest economies.
The US economy grew by 3.3% in the fourth quarter of 2023, which was much better than expected.
That put the US at 2.5% over 2023 as a whole, the best performance of all other advanced economies. It is also expected to outperform the rest of the G7 in 2024.
In October 2023, the International Monetary Fund (IMF) predicted that the UK would grow by just 0.6% in 2024.