Last minute additional day - three FPs or just one at a time?

[goNsoon2WDW]

I am going with a friend in a few weeks for five days and we have three-day tickets. I am considering the possibility of adding another day to our tickets, but won't know until the day before (maybe two). Since I only have a three-day ticket, I can't get fast passes in advance. When I add the extra day, will I be able to get three FP or only one at a time?
TIA

 

[Lucius Best]

If you have three day tickets, you can book 3 FP for any three days of your five day trip. If you add a 4th day, you can then get 3 FP for a fourth day on your trip. You want to add the 4th day as early as possible to increase your choices.

 

[CAS239]

Yea, add your 3 day tickets to your MDE and select your 3 days worth of FP's. If you decide you want to add more days on, whether now or while at the park, add those tickets as well and then select your FP's

As long as you have tickets linked you can select FP's.