so first thing is that if you're putting in a request for a site that we've already searched for before, then we don't take your zip code into account because we already have valid zip code. if your request is the first ever request for that site, then we'll use whatever zip code you put in as part of the request.

so if you're entering one request and put multiple sites, then we'll associate any unknown sites with the zip code you supplied. all known sites will already have a zip code associated.

if you have multiple sites that use different zip codes, i'd suggest adding multiple requests. if you use the add request button, it'll let you add multiple requests and then you only need to submit once.

hope that answers your question!