With CGT at 33% and income tax between 20% and 40% here are the most tax efficient approaches I am aware of:
1. Find an investment that can be held long term, that is subject to CGT.
An option here is a conglomerate which imitates an ETF but does not have deemed disposal tax.
Pay the 33% CGT on gains whenever it is sold. Sell the tax free allowance amount €1,270 each year it has gone up, then possibly reinvest it.
2. For those with low income or solely living off investment returns - find an investment where the returns is classified as income, rather than capital gains. I am not well versed in such investments so feel free to share.
Utilise tax free allowance (the first €1,700 of tax) and the lower tax band tier (20% up to €36,600).
3. Utilise approach 1 above, but travel for 4 years when you are at the age you need to sell the investments. You can still spend up to a few months in Ireland each year. Sell it in year 4 when you are no longer an ordinary tax resident of Ireland, ideally paying little to no tax in wherever you decide to become a resident in this time. You can become an Irish resident from year 5 onwards.
Obviously option 3 is extreme, but would suit some with a large net worth and no urgent need to be in the country.
Either way the CGT of 33% is extortionate and leads us to search for ways to minimise it.
Please share any other approach that you have considered or taken.