When should I cancel my renters insurance?

The sources we read do not say what day you should cancel. They explain what a cancellation is and what you get back. The Texas Department of Insurance says cancellation means you or the insurance company stops coverage before the policy's end date [1].

If you cancel, Texas says the company must refund any unearned premium to you within 15 days after the date of the cancellation [2]. Unearned premium is the part you paid in advance that did not go toward coverage. California warns that broker fees are often non-refundable even if you cancel [3]. Check your fee agreement.

A practical step is to keep the policy until your things are out of the old place and any new policy has started, so you have no gap. The sources do not say this, and they do not say whether roommates need their own policy. Your lease or your landlord may also require coverage. Ask them.

Read the cancellation part of your policy and your lease. The Texas rule applies to Texas home policies; your state and your policy may differ. Whether a roommate needs a separate policy, and when a lease requires coverage — "Don't know yet".