You pay tax if your total annual income adds up to more than your Personal Allowance. This includes pension income.
What you’ll pay depends on the total income you get from all sources each year, like income from other pensions and other jobs.
If you have questions about how much tax you pay, or you think your tax code is wrong, phone HM Revenue and Customers on 0300 200 3300. They might ask for the Pay As You Earn (PAYE) reference for the Fund, which is 120\HB01721.