AVC Lump Sums
The Revenue are not concerned where the money came from so long as you did not borrow the funds.
Any lump sum invested, in so far as it exceeds that year's limit (say 30%) will be spread forward into future years. So next year relief would be given on another 30% of earnings, until eventually all the investment was relieved. The maximum spread period is 5 years, but it could be relieved over a shorter period depending on the amount invested.
If however after putting in the AVC investment, you retired, then it cannot be spread forward, and at that stage the Revenue will sread back the amount, at the rate applicable each year ( say 15%),until the full amount is relieved. How long this takes before you get a tax rebate will vary, but presumably it should only be a matter of weeks.
The attraction of putting in a lump sum AVC just prior to retirement is enhanced if the AVC fund can subsequently be used to increase the tax-free lump sum available on retirement (for example if the individual has earnings that are not pensioned in the main scheme, such as BIK or bonuses). Such earnings are "pensionable" under Revenue rules and the AVC could be used just to fund the additional tax-free lump sum of 150% of such additional earnings.
Conan