Eamonn Ferguson

England changed its organ donation law in 2020. All eligible adults are presumed willing to donate their organs after death unless they opt out. The change was intended to increase the supply of donated organs, but 8,746 people in the UK are still waiting for a transplant, and just 1,650 transplants have taken place since April 2026.

This year, NHS Blood and Transplant, which manages organ donation in England, issued an urgent appeal after donation fell by 9%. So why has opt-out not delivered?

Opt-out is often held up as one of nudge theory’s big successes. A widely cited 2003 paper found that countries using it had higher donation rates. But recent studies have not supported that advantage.

To understand why the change has not had the expected effect, it helps to look at how the law works. Under England’s system, every eligible adult is treated as a donor unless they record a decision not to be. If you do nothing, you are classed as having “deemed consent”. (Confusingly, you can still opt in by registering a wish to donate.)

It is also a “soft” opt-out, which means your family has the final say. That makes conversations with relatives just as important as anything on the register, because a clear message from you, whether through the register or over dinner, tells them what you wanted.

The figures show what happens in practice. In England, 39% of eligible people have opted in, and 4.3% have opted out. The remaining 56.7% fall under deemed consent.

That last group is important because families often rely on what they know about the person’s wishes. When someone had opted in, families agreed to donation 87% of the time. Under deemed consent, that falls to 46%, and it is 0% when the person had opted out.

Across all cases, family consent has fallen from 69% in 2020–21 to 59% in 2024–25.

Why are families more likely to say no when consent has only been assumed? One possibility is that relatives are less certain about what the person wanted.

A recent study found uncertainty was higher under deemed consent, but that did not explain the lower consent rate. Instead, the factor that did explain the difference was “anticipated regret” – how bad relatives expected to feel if they made the wrong decision by not consenting.

The same study found that the relative’s own views also affected whether they agreed to donation. If that person feels negatively about donation, they are less likely to agree.

Researchers have suggested another explanation: the “lone-wolf effect”. Seeing others leave a register, or hearing negative views, pushes people to opt out more strongly than seeing others opt in draws them in. The latter is known as the good-shepherd effect.

Opt-out may also change how people think about organ donation. To some, a gift starts to look like state-sanctioned theft, while to others it becomes something mundane and everyday. Either change could make people less likely to opt in and more likely to opt out.