Entering semi-retirement - what now?

[Kiro]

No real deadline to sign up, and you can choose not to (but if you’re entitled to, why not eh?). The sooner the better but you need a document from your company (forgot the name, it says what was the reason for you leaving and a bunch of other stuff) and that take a week or 2 so you should tell your company in advance that you need this paper.

Once enrolled you want hello work to give you a paper to bring to the city hall in order to get the health insurance unemployed person deduction (previous year salary counted at 30% for health insurance calculation).
Before that, do the math on which is best (ask your company, ask city hall).
Unless you’re making an outrageous amount, getting the unemployed deduction will likely be better financially.
For me it was always better that way anyway.

Nenkin is compulsory, you’re automatically enrolled. Go tell the pension section at the city hall to send you the bills.
Unless you decide to become your partner’s dependent (if your partner is an employee) and get “free” pension/insurance.

[Tkydon]

No real deadline to sign up, and you can choose not to (but if you’re entitled to, why not eh?). The sooner the better but you need a document from your company (forgot the name, it says what was the reason for you leaving and a bunch of other stuff) and that take a week or 2 so you should tell your company in advance that you need this paper.

Once enrolled you want hello work to give you a paper to bring to the city hall in order to get the health insurance unemployed person deduction (previous year salary counted at 30% for health insurance calculation).
Before that, do the math on which is best (ask your company, ask city hall).
Unless you’re making an outrageous amount, getting the unemployed deduction will likely be better financially.
For me it was always better that way anyway.

Nenkin is compulsory, you’re automatically enrolled. Go tell the pension section at the city hall to send you the bills.
Unless you decide to become your partner’s dependent (if your partner is an employee) and get “free” pension/insurance.

As the Household Maximum National Heath Insurance Premium is now Y1,060,000 per year in 2024 (nationwide), and that is about 12% of Household Income, but includes the Per Household and Per Insured Person contributions (depends on where you live), then...

Y1,060,000 / about 0.12 = about Y8M...

Therefore, if your Total Household Taxable income was more than about Y24M in the previous tax year, even with the 30% health insurance calculation, you'll still be at the top level; Y1,060,000 per year or Y106,000 per month for 10 months of the year with March and April off... payable from May of the year after you left to Feb of the year after that...
(depends when you left... you may have up to 15 months = upto 5 months based on 2 years' prior income, if you left in the latter end of the year (Oct - 5 months, Nov - 4 months, etc...), and 10 months based on last year's Total Household Income), before you see your premiums come down due to reduce household total income after you left.