Very stupid travel insurance Q

[IbizaToTheNorfolkBroads]

I have an annual travel insurance policy that expires on 18 July,
i don't want to renew with that company.

If I pay for a holiday in August now, do I need to take out a new policy now, or beofe 18 July?

ie: will my existing policy cover me for cancelation of a holiday that starts after it expires?

I can't see anything obvious in the paperwork

By 18th July. Your existing policy will cover if you have to cancel between now and 18th, new policy would apply if you cancel after the 18th.

Thank you