At what point do I inform our insurer...Now, or after the police create a final report for both the Insurers or when it comes up for renewal?

The best bit of advice I’ve been given (reference insurance) was to inform my insurers of a minor non-fault accident I had. The other party told me at the time they wouldn’t pursue a claim, even though they hit me! A friend of mine advised me to call my insurers and tell them it was for ‘information only’. Six months later the other party issued me with a county court summons claiming £3,500 neck and back injuries and £2,000 vehicle damage! My insurance successfully defended it all the way to court and the other party ended up paying costs of £7,200. I would now always inform my insurers of ANY accidents/incidents even if it was a different company or policy.