A bit open ended on AVCs but really good to avoid moving into the higher tax brackets, so good to raise the amount every year before you get a rise due to cost of living or a scheduled increment.
Then there is the separate questions on:
- what to invest in
- how to draw them down when you retire.
- Massive increase in contribution on your final year/s
1. No idea, I split mine 4 ways with different risks and investing in different things. Whatever you do it's a gamble that you may have taken too much risk or not enough.
2. Depends how much you have and are they a bridge to deferred DB pension/what other income or pensions you have due to tax thresholds and allowances.
3. Some pay the majority into AVCs the last year or two, even get a loan to live on then pay it off, especially if a good proportion subject to 40% tax or more. Obviously it can be done without a loan, and a lot of schemes ensure you can't leave yourself less than minimum wage after AVC contributions.
They are a no brainier to avoid 40% or even 20% tax if you can afford it.
If you change jobs a lot, even with the same pension scheme but different employer they stop and start so there will be gaps of several months were you can contribute. If you change employer and scheme, and need to transfer pensions, the AVC contributions will stop for at least a year, so worth bearing in mind if close to retirement.