Another important detail to check is your tax code, which is usually made up of several numbers and letters. It tells your employer how much tax to deduct from your pay. If your tax code is wrong you could either overpay (and be entitled to a rebate in the future) or underpay and be faced with an unexpected bill further down the line.
If your tax code is 1000L,1000L W1, 1000L M1 or 1000L X, check whether you've been put on the emergency tax code. This often happens when you start a new job and your employer is waiting for HMRC (Her Majesty’s Revenue & Customs – otherwise known as the tax office) to send them the correct code. Emergency tax won’t take into account any allowances or reliefs you're entitled to, other than the Personal Allowance, so you could end up paying a chunk more than you're meant to.
You can normally be moved to a more suitable code quite quickly by providing a bit more information about your income for the current tax year. But remember, 1000L is also the tax code you'll have if you're only entitled to the basic Personal Allowance. Visit the HMRC for more information on emergency tax codes.