Texas · The end date on the notice is the coverage date
A cancellation ends the policy early. A nonrenewal lets it run out and then stops.
Mid-term cancellation cuts the contract before the expiration you already paid toward. Nonrenewal means the company will not offer the next term. You canceling, to move to another carrier, is a third event. The legal reason a company may use, and how many days of notice you get, are in the policy and in Texas law. This page does not invent that number. Read the date on the notice. This is not legal advice.
If you are the one leaving, cancel only after the new policy is bound. How to do that without a gap: canceling a Texas auto policy. What you are replacing: car insurance in Texas and Texas auto. If you think the company broke a rule, the complaint path is TDI, not a second claim: TDI consumer help and the complaint form. The plain-English difference, from the Insurance Information Institute: cancellation versus nonrenewal.