Unpaid carers save the British state around 184 billion pounds a year. That is a second NHS, run for free, and the sums quietly depend on it.

There is a number in the British economy that almost never gets said out loud, and it is one of the largest of all. Unpaid carers, the people looking after an ill, disabled or older relative or friend, provide care worth an estimated 184 billion pounds a year across the UK. That figure, from the Centre for Care and Carers UK, is not a rounding item. It is close to the entire NHS budget. We run a second health service, and we pay the staff nothing.

Start with who they are. The 2021 Census counted about 5.8 million unpaid carers in the UK. Around 1.7 million of them provide fifty hours a week or more, which is more than a full-time job, without a wage, a pension contribution or a day off. Carers UK estimates that 2.6 million people have given up paid work to care, at a rate the charity puts at roughly 600 a day.

Now follow the money, because this is where it lands on the public finances rather than on a family. When a carer leaves work, three things happen at once. The Treasury loses their income tax and their national insurance. The economy loses their output, which one study for the Carers Trust put at around 47 billion pounds a year in lost work alone. And the individual, very often, slides toward hardship: Carers UK finds 1.2 million unpaid carers already living in poverty. So the state is not banking 184 billion pounds cleanly. It is booking a vast saving on care it does not provide, and quietly absorbing the cost of the people it wears out in the process.

Here is the part that connects to everything else this paper has covered this week. Two forces are about to push in the same direction. The population is ageing, so demand for care is set to rise sharply, toward a projected nine million carers by the late 2030s. And AI is thinning exactly the kind of paid, office-based work that used to give a mid-life carer something to go back to. The jobs that flex around caring are among the first the machines take. So the pool of people needing care grows, the paid work that let carers combine it shrinks, and the unpaid workforce that fills the gap is asked for more.

Successive governments have known these numbers and deferred them. The Casey commission on adult social care, set up in 2025, is due to report its first phase around the middle of this year, with the long-term plan not expected until 2028. That timetable tells you the priority. Meanwhile the saving keeps being booked, silently, in every fiscal forecast, as if 184 billion pounds of work will simply keep turning up for free.

It might not. Carers UK has warned that if even a small share of unpaid carers stopped, the system would not cope. That is the real exposure hiding in the nation's accounts, and it is nowhere in the growth plan.