Last year, when I changed car insurers I had 9 (or more) years no claims
discount. I had this on my certificate/renewal notice. However, this
year, the different insurer now just puts 5+ years on the notice.

Now, I do have 9+ years no claims discount, and I have all previous
insurance certificates/renewal notices showing I should have 9+ years
discount.

I've done insurance searches on 9+ years and 5+ years discounts, and
many are the same, but one or two are higher with just 5+ years.

Am I likely to convince an insurer that I really do have 9+ years
discount by showing last years 9+ years renewal/certificate and this
years 5+ years renewal/certificate?

Thanks

David