I've just renewed my car insurance and I just noticed that my last couple NCD certificates, from my insurers since 2017, have been saying 9 years. It only clicked today seeing it on CompareTheMarket and thinking about it, that I have owned my own cars for 12 years with no claims, so that is what my NCD should be based on. Reading around, I now understand that most insurers cap the NCD at 9 years, but others account for more, not that it makes a huge defference in £££ - maybe 5%/£20 or so. Is there any point in the effort going back to past insurers asking them to amend the NCD certificates for 2017 and 2018 to show the correct years accrued, regardless of whether they count it or no? Or do I just suck it up just accept the three lost years?