This is an interesting question! Thanks for putting it out there!
Lots of variables, plenty of tax considerations, etc, as you mention. I haven’t punched the numbers - so please expect no useful contribution here - but I wanted to share this anyhow:
As others have mentioned you still pay into the AHV insurance until 65 (64 for women, currently) if you stop working and the amount you (should)* pay depends
- whether you have a spouse and whether they still at least pay twice the minimal AHV contribution (currently about CHF 1k per year)
- on your wealth
- on 20 times the yearly pension income you receive
The corresponding guide by AHV/IV was already linked by @rolandinho.
IIUC, assuming that you do not have a spouse who pays at least twice the minmal AHV contribution, this means that for collecting AHV at 63 and 64 you’ll still have to pay into AHV, and the amount is based on
- age 63: CHF ~3000k (CHF 2500k portfolio + 20 times AHV pension of CHF 25.4k)
- age 64: CHF ~3040k (CHF 2500k portfolio + 20 times AHV pension of CHF 27.4k)
The table in the linked guide doesn’t have explicit numbers for this in their Beitragstabelle, but extrapolating from the figure for CHF 1500k (and saucing on some nice progression) you end up paying between 7k and maybe 9k into AHV for those years before turning 65.
Of course any additional pension income from pillar 2 or a bunch of other things affect this calculation as well.
Wow, that was just the part for receiving AHV before the regular pension age.
Whole different set of questions and calculations for waiting until 70 for AHV payout. I’ll have to think about this more thoroughly … seems like the AVH expected per year pension increase is just around my expected per year dividend increase of my portfolios (although the AHV pension increase seems more guaranteed … but OTOH I’ll benefit from additional nest egg capital appreciation … or, ahem, write-down).
If I manage to punch some actual numbers, I’ll post them here. The question is certainly super interesting (probably though only if you’re nearing the decision year :-D).
* Another wrinkle for the entire calculation is of course to forego some percentage of the AHV pension for years not paid in. Does your expected return on contributions missed exceed the one promised by AHV? Wrinkles after wrinkles …