When money is taken out of the pension pot, any growth in its value is taxable, whereas it will grow tax-free within the pension pot.
You might want to take your entire pension pot in one go for any number of reasons. For example, to clear debts, pay for a holiday, or splash out on a big purchase.
But be aware that it will reduce the money you’ll have to live on when you retire. And you could end up with a big tax bill.
So it’s a good idea to work out the tax you’ll pay beforehand, so you don’t get a shock.