What do I tell insurance about how much I paid for my vehicle on the insurance

[The Engineer]

theft questionnaire? I got the vehicle from a private owner and I put less than I paid for the vehicle on the title so I would pay less taxes. My vehicle got stolen, do I have to tell the insurance that I paid the same value on the title or tell them what I actually paid. I dont have any paper work stating what I paid, it was paid in cash. The insurance hasn't asked for the title but im concerned they will and they will see what the sale price is even though it isnt true.