change home insurance, mortgage implications

I recently changed the company I have my home insured with. I am not sure, but do I need to make my mortgage company aware of this change?

Yes. You need to have their interest noted on the policy. They may have specific forms for this.

its normally one of the questions on the form. If not the lender will pick it up as the old insurer will advise of cancellation

As mentioned above the lender's interest in the property must be noted on the policy document/schedule by the insurer. The lender will also then need a letter of indemnity from the insurer. I can't remember if the insurer sends this directly to the lender or if it sends it to the policyholder who then must send it onto the lender. I think it's the latter since I don't recall the insurer asking for mortgage account number etc.