Hey there Misdee,
Welcome to planDisney and thanks so much for this question! I'm happy to hear you're planning a group trip to the Happiest Place on Earth later this year - it's always fun to visit the Disneyland Resort with family and friends.
I certainly understand that plans can change, especially with a large group, luckily you have a few options for flexibility when planning for your visit.
Currently, you need both valid
theme park tickets and a
theme park reservation for each day you plan to visit the parks. Once you've purchased a theme park ticket, it just
needs to be used by the expiration date (which is typically a year or more out from the purchase date) and it is nonrefundable.
However, your theme park reservations are extremely flexible and you can change them quickly and easily through the
My Plans hub on the Disneyland Resort website. As you continue to plan your trip, the My Plans page is a helpful tool to make and manage all the different reservations you might want to make for your group!
When you purchase park tickets through the Disneyland Resort website, you will add a name associated with the tickets, but this is more to help you keep them organized - it does not dictate who has to use the ticket. When you arrive at the Disneyland Resort on the first day of your trip, a Cast Member at the entry gate will take a quick picture of each person that will be assigned with their ticket, and this is what is used to ensure the same person uses that ticket for its duration.
Therefore, in the event that someone in your party decides not to join you, then you can simply have someone else in your party use their ticket when you all arrive.
Thank you again for your question, Misdee! I hope you and your group make new magical memories during your visit this summer. Make sure to stop by to see us again here at planDisney if you think of any other questions we can help with!
Have a Magical Day,
Greg