A decade after Britain’s historic vote to leave the European Union, the full cost of Brexit is still being tallied, and the picture that emerges is far from rosy. Analysts broadly agree that the British economy is smaller than it would have been had the country remained in the bloc, weighed down by reduced trade and weaker investment.

As the U.K. marks ten years since the June 23, 2016 referendum, the economic damage continues to accumulate, accompanied by a wave of political turmoil that shows little sign of settling.

A Warning That Was Right, But Wrong on Timing

In the run-up to the referendum, the government of the day issued a dire prediction: voting to leave would trigger “an immediate and profound shock” to the economy. By a narrow margin, voters chose to leave anyway.

That warning turned out to be accurate in substance but mistaken in timing. Rather than an instant collapse, Brexit’s damage has unfolded gradually over ten years, with the costs steadily mounting and, according to economists, far outweighing any benefits.

The disruption hasn’t been purely economic. Brexit has also fueled remarkable political instability. Britain is about to welcome its seventh prime minister since the vote, following Keir Starmer’s resignation announcement on Monday.

A Nation Growing More Doubtful

The turbulence has bred a growing sense of regret among the British public.

Recent polling captures the shift in mood, revealing that:

• Nearly half of Britons now say Brexit is going worse than expected, a sharp increase from five years earlier
• Just over half would support rejoining the European Union

These figures suggest that, a decade on, public enthusiasm for the decision has cooled considerably.

A Smaller Economy Than It Should Be

Pinning down the precise cost of Brexit is difficult, given the other shocks Britain has absorbed since the referendum, including the Covid-19 pandemic, Trump’s tariffs, and the wars in Ukraine and Iran. Even so, economists have made serious attempts to isolate its effects.

Part of what initially masked the impact was timing. In 2016, the government assumed leaving would mean an immediate rupture of trade ties. Instead, years of negotiations followed. Britain didn’t officially leave until the end of January 2020, and even then an 11-month transition period delayed real change until 2021, four and a half years after the vote.

Despite the difficulty of untangling Brexit from other events, the estimates are sobering:

• One widely cited study led by Stanford professor Nicholas Bloom estimated Brexit reduced Britain’s GDP by up to 8 percent, with the impact building gradually over time
• Broadly, economists agree the economy is roughly 4 to 6 percent smaller than it would have been inside the EU
• The Office for Budget Responsibility believes Brexit will cut Britain’s long-run productivity by 4 percent

A smaller economy means lower tax revenues to fund public services and a slower rise in living standards.

New Trade Deals Haven’t Filled the Gap

Much of the economic pain stems from added friction with the EU’s market of 450 million people right on Britain’s doorstep.

A 2021 trade agreement kept tariffs mostly at zero but introduced new barriers in the form of extra paperwork, border checks, and regulations. The consequences for trade have been significant, with the Centre for European Reform finding that Brexit reduced Britain’s exports of goods and services to the EU by about 12 percent and imports from the bloc by about 16 percent.

Some sectors have been hit especially hard. British agriculture and food exports fell by nearly 30 percent, and for certain producers, such as shellfish farmers, the added border checks made exporting simply unviable. Many small businesses have scaled back their efforts to win European customers due to the extra time and cost involved.

Britain has used its newfound freedom to sign its own trade deals, reaching 39 agreements covering 72 countries. Yet these have not compensated for the lost trade with Europe. The EU remains Britain’s largest trading partner by far, accounting for more than 40 percent of its trade. Tellingly, the Office for Budget Responsibility simply assumes that new deals with non-EU countries will have no material impact.

Businesses Still Feeling the Strain

The Brexit vote delivered an early and lasting blow to business investment, as companies pulled back amid the uncertainty of prolonged negotiations and political instability.

Investment eventually recovered, but not as strongly as it otherwise might have. The National Institute of Economic and Social Research recently estimated that Brexit-induced uncertainty has reduced long-run business investment by around 4 percent.

As for winners, they appear to be few. Anton Spisak of the Centre for European Reform noted that consultants, lawyers, and customs agents have benefited, but he emphasized that the overall effect on the economy has been very negative.

The Migration Surprise

One of the most striking outcomes has involved migration, which unfolded in a way many Brexit supporters did not anticipate.

Rather than reducing immigration, Brexit has coincided with a large influx of people from non-EU countries. These newcomers face different visa requirements and bring different skills, reshaping the labor market in the process.

Several industries that once relied on EU workers have struggled with added costs and disruption, including:

• Hospitality
• Food processing
• Health and social care

As economic geographer Sarah Hall of the University of Cambridge observed, the country is only in the early stages of understanding how this profound shift in immigration patterns will ultimately play out.

London Holds On as Europe’s Financial Hub

There is at least one area where the feared damage has been contained. Back in 2016, the financial services sector strongly opposed Brexit, fearing it would undermine London’s role as a gateway to Europe.

A decade later, London has retained its status as Europe’s biggest financial center, with no rival city emerging as the industry’s clear new destination. Still, it hasn’t escaped unscathed. London has lost chunks of business, including some stock trading to Amsterdam and asset management to Dublin.

Hall likened the effect to “a slow puncture,” describing not a sudden exodus but a steady series of relocations and, increasingly, new job openings that are happening outside London rather than within it.

Looking Toward the Next Decade

As Britain grapples with stubborn inflation, a heavy debt burden, and higher borrowing costs, the appeal of reversing some of Brexit’s effects has grown. Notably, Andy Burnham, the front-runner to become the next prime minister, has called Brexit “damaging.”

Yet meaningful change appears unlikely in the near term. Starmer’s government held a summit with European leaders last year to “reset” the relationship, but progress has been slow, and a follow-up summit planned for next month was postponed by the Europeans after his resignation. Meanwhile, the Labour Party has ruled out rejoining the single market and customs union or restoring freedom of movement, and there is limited appetite in Brussels for deep renegotiation.

The Hardest Cost to Measure

Perhaps the most significant consequence of Brexit is also the most difficult to quantify. According to Spisak, the most important cost is the opportunity cost, all the things that simply never happened because of Brexit.

While he acknowledged that much could change over the next ten years, he does not expect major shifts in the next two or three years before the next general election. Until then, the costs will keep accumulating, quietly and steadily, much as they have for the past decade.

The Bottom Line

Ten years after the referendum, Brexit’s legacy is one of gradual economic erosion paired with persistent political upheaval. While Britain has avoided some of the worst-case scenarios, such as losing London’s financial crown, the broader story is one of a smaller economy, diminished trade, weaker investment, and a public increasingly questioning the decision. As the U.K. looks ahead, the lingering question is not just what Brexit has cost so far, but how much more it will cost in the years to come.