When I first arrived to Japan in 2016 I didn't really understand the pension system. I thought that, as in my home country, it was automatically managed by the company and when I started receiving bills I asked a coworker and he told me it was safe to ignore them. A year and half later I got a huge bill and went to the city office to ask about it. They explained that I wasn't registered in company pension and that I had to pay into the national system. It was a really big amount and at that moment I didn't have the money to pay it so they said it was fine, I could pay a few owed months and start paying normally from then on, which I did. I didn't really understand it was actually a deferral to pay later, I thought it was just forgiven.
9 years later, checking the myna site, I saw the year with 0 payments and remembered what had happened. I started asking around and investigating online and I discovered that if it was a deferral I had ten years to pay it. I called the city office and they said no, it's a two year limit. I looked around my files, found the original documents, saw the months marked as menjou, called the pension office and they told me yes, I can still pay it but by the skin of my teeth as it's at the very limit.
From what I've read online it's 0.7% interest per unpaid month so, 18 months, 16400 yen per month, after 10 years would be around… 600,000 yen? There's no way to avoid paying the full interest rate? I understand that ultimately it was my screw up, but it's quite a bit of money and if there's a way to maybe pay a little less it would be nice.
edit: some things I forgot to mention. i have a 2017 nenkin blue slip with the year payment information that has jan 2017 to apr 2017 marked as 全額免状. Another nenkin document, an official full A4 sized paper, has 2016 months up to April 2017 marked with capital Zs and then after that capital As, for which in the payment information slip show as paid. I have no nenkin payment slip for 2016 though.
by UnintendedPunther