Not much of an answer, but FWIW - based on my knowledge - there's unfortunately NO really international solution for "tax advantaged retirement saving".
- Unfortunately each jurisdiction only offers a tax-advantaged-retirement scheme in their own jurisdiction. Indeed as you mention in the UK case, once you happen to leave, you're done, they cancel it or minimize it one way or another.
I feel the best you can do is
Create a savings account (perhaps with a brokerage or similar, or even just a plain bank) in some neutral, international jurisdiction. A natural for this is something like HSBC, which exists to cater to the world's major criminals international dwellers.
No matter where you are living/working, save your 20,000 a year in to that account
Note that there is NO front-side tax advantage here. You are completely removing yourself from national tax-advantaged-retirement schemes, wherein, you can "deposit tax free" and so on. You can only send that 20,000 after paying all the local normal taxes.
However ... when you eventually retire:
Depending greatly on your retirement situation, you may well enjoy (very) substantial back side tax advantages.
For example. Say it turns out in life's journey you end up marrying someone from, who knows, Dubai or New Zealand or such, and you end up retiring there with little or no connection to the UK. In fact, in many such places, all that money in your HSBC Jersey account is just yours. Nobody wants to know about it or otherwise, it's just your money. NO capital gains tax at all, no nothing. Conversely of course, if you end up in France or such, you've simply "made a good investment" and will (likely) have to basically pay "capital gains tax" like any other time in life you make money.
One problem is,
- Some countries, notably the USA, actually "don't let you" have accounts overseas, or it's problematic, you have to report any and all overseas assets etc. So this is a factor depending on places you live.
Don't forget that
- We mentioned "front-side" tax advantages. You get none of those. We mentioned back-side tax advantages: this can be massive depending on where you end up. But don't forget you do get along-the-way tax advantages. Your account with DBS in Singapore is "ALL YOURS", it builds endlessly with zero (0.0) withdrawls from taxes or fees each year along the way. Look at all that building!
Advantages
There are advantages along the way. That 20k a year will quickly become a fatass pile of dough. More and more commas. The good thing is, just like other major criminals international dwellers, once you have a good balance, companies like HSBC will welcome you with open arms as a "premier" / whatever branding term customer, and you enjoy even more privacy benefits and services. Often these are surprisingly beneficial.
Another good thing is, it's quite handy to have a pile of cash elsewhere. Say you happen to take a holiday in Dubai, Singapore or whatever it is. All that money is there for you. Additionally over the years you may prefer to (say) buy a flat or who knows what in some global locale. Once again - depending on where you end up - this can be hugely advantageous.
Again, just to repeat ..
not much of an answer, but FWIW - based on my knowledge - there's unfortunately NO really international solution for "tax advantaged retirement saving".
You have to distinguish between "front" "middle" and "back" advantages in tax advantaged retirement savings schemes; as I outline some (but not all) of the three area available to you if you adopt a "PT" lifestyle.
