Your lifetime allowance is the total capital (cash) value of all pension benefits - not just from the LGPS - you can have before you'll be asked to pay tax on them. If the total value of pension benefits when you draw them is more than the allowance, you have to pay tax on the excess.
Not many members of the LGPS are affected. The lifetime allowance for 2013/14 was £1.5m. It was £1.25m in 2014/15 and 2015/16. It was £1m in 2016/17 and 2017/18. In 2018/2019 it is £1,030,000.
It is possible to protect the level of lifetime allowance, see Protecting your lifetime allowance.
When a pension starts to be paid you use some of your lifetime allowance, so you need to keep a record of any pensions you receive.
When you draw your LGPS pension, we will ask for the percentage of your lifetime allowance which has been used up by any other pensions. If you don't answer this promptly, it could delay your payment.
This is the amount you have to earn before you pay any National Insurance. For 2018/2019 the lower earnings limit is £6,032 pa.