You can't simply just enter another park with it. I'm sure you could exchange it for another park ticket or park hopper with no problem though.
https://disneyworld.disney.go.com/help/phone/
Try calling "existing tickets" and see if they know. Also, if you are staying on property, you can call your resort directly and speak to the concierge who tend to be very knowledgeable about tickets.
It's a regular ticket from what they said. It will be mailed to me this week so I will know more then. It better be a regular ticket because I paid for one. I will let you know when I get it.If the one-day ticket is a complimentary one, then you can't upgrade it. For Disney's purposes, a comp ticket has no monetary value.
The ticket would actually have the word "COMPLIMENTARY" printed on it.
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