The process of bringing all your pensions together is called consolidation. It is often referred to as a transfer. Most companies will allow you to do this.

There are a number of advantages to this approach. For example:

You’ll only have to deal with one provider which could make life simpler

If you decide to buy an annuity when you want to take benefits, you’ll only receive one payment each month (if you choose to have your income paid monthly), this can feel more familiar as it will probably mirror how your salary was paid

If you're likely to buy an annuity, you could receive a better annuity rate as your account will be bigger and some companies offer better rates depending on the size of your pension account

This is not an exhaustive list of the issues you should bear in mind. If you are interested in consolidating your pension accounts, it could make sense to take financial advice.

There are a number of issues to consider before you decide to consolidate:

Make sure there are no penalties if you transfer your account from one provider to another
Some companies offer ‘Guaranteed Annuity Rates’ and these can provide a much higher income than today’s annuity rates might offer. Any ‘Guaranteed Annuity Rate’ could be lost if you consolidate your pensions. You should check with your pension provider 
If you’re in a final salary or defined benefit scheme you don’t need to buy an annuity because final salary pensions aim to provide a known and guaranteed level of cover. If you are in one of these schemes stop to think about what you may be moving away from. Furthermore, transfers can generally only be made from final salary schemes after receiving advice from an authorised financial adviser