If you are buying extra pension by paying Additional Regular Contributions (ARCs)

When you draw your pension you will be credited with the extra pension that you have paid for. This will increase the value of your retirement benefits.

However, But if you are paying ARCs when you retire and qualify for the type of ill health pension where your benefits are enhanced (Tier 1 and Tier 2 ill health pensions), you will be credited with all the extra pension that you set out to buy, even if you have not completed full payment for it.

If you choose to retire early and draw your benefits before age 65, or you are retired on redundancy or business efficiency grounds before that age, the extra pension you have bought will be reduced for early payment. 

If you draw your benefits on flexible retirement, you can, if you wish, draw all the extra pension you have paid for, although it will be reduced for early payment.  If you choose to draw the extra pension on flexible retirement, your ARCs contract will cease (although you will be able to take out a new ARC contract).   

You can choose to exchange some of the extra pension you have bought for a cash lump sum in the same way as your main LGPS pension.