Thank you everyone that's exactly what I needed to know. I did check over my shoulder, I realise I left that out of my account above but I said that to my insurers. My car is a new 4x4 and it has large mirrors with those extra bits of the mirrors that mean you have a better view. I'm my opinion the other party was not in the lane when I moved over but I understand now none of that matters as reallymadwoman said 1% or 100% fault has the same implications. The person at the insurance company said that if the other persons claim was for £100 or £10000 it would make the same difference to my renewal price. Is that true? My renewal is due next month, what do I put when asked about the value of an outstanding claim?

I hope someone can help with the below. This is all new to me and it's making me very stressed! I was involved in an accident a month ago. This is my version of events. I drove down a slip road then joined a dual carriageway. Shortly after this I overtook the car in front. I checked mirrors and it was safe to change lanes. As I was moving into the lane I felt a collision take place. Looked in my rear view mirror and saw a car behind me. They have damage to their front passenger side wing (small car). I had a scuff on my rear driver side alloy (I have a 4x4) but no actual damage to my car so will not be claiming. In my opinion they were not in the lane when I started the manoeuvre. I have said I assume they were in the same lane as me but then we both moved to overtake at the same time. The driver of the other car was very young with a brand new car. For him to come out of knowhere I think speed was a part of it but insurance said they are not interested in that. Initially I was told any claim would be a split claim. Now I have been told the other party have said it was all my fault, I drove into their lane etc. My insurance company are saying that it will go as 100% my fault as its up to me to make sure it's safe to pull out (I did the lane was clear!) and the other person was more established in the lane based on their version of events. There are no witnesses or cameras. I have said I do not accept 100% that it was my fault. I've been driving for 18 years and I guess I'm lucky this was my first accident and lucky my kids were not in the car. Also a lesson learned is to to have my dashcam turned on as I had unplugged it! I just want to know what happens now? Do I have to accept this? How does it affect my renewal (due soon!) if a claim is 100% my fault or say 50% my fault? Thanks for any advice in advance.