The short answer—it depends. It depends on the policy(ies) at issue, the type of claim, the type of policy, the coverage problems at issue, etc. If you’re really concerned, talk to an attorney.
That being said, here are some guidelines to include in your notice letter.
First, if you know the policy(ies) numbers that are implicated, you should include those. I suggest you also state “and any other applicable policies.” You may not know initially which policies are actually triggered and at issue at the start.
Second, it is helpful to identify the person or entity covered under the policy. This, (along with the policy number(s)) assists the insurer figure out the policies that are at issue.
Third, you should include description of the claim. If you’ve been sued, I wouldn’t characterize the lawsuit. Doing so could impact the coverage analysis. Just inform the insurer that you’ve been sued and attach a copy of the complaint. If there’s been an accident, I’d follow the same guidance. Just say you’ve been in or had an accident. You can identify when, where, and the contact information of others involved. You can attach a police report if available. I wouldn’t address who you think was at fault.
I think it is a good idea in your notice to request a “Certified”
copy of any applicable policies. In Indiana, insurers have an obligation to do
provide you a copy. If they do not, they could lose their coverage defenses.
If you already have a lawyer, a contractor, etc. involved,
let the insurer know who you’re using. Request the insurer to advise you if
they suggest someone else. I’d also state that you’ll forward the insurer their
bills. This helps minimize a potential subsequent argument that you didn’t use
the right person/organization.
I would send this letter certified mail so that you have proof you sent it and when the insurer received it.
Finally, I would also send notice to your insurance agent/broker. Ask them to pass the notice letter along to any potential insurer. I’d also ask them for copies of the policies as well.
Good luck. As always, this is not legal advice.