So I buy 5 day ticket for WDW. I swipe my finger the first day I use it? Than, the rest of the day I swipe it again as I enter the park again? Than, the next day I enter, I must swipe again and it must match the print from the previous day? Or is the data erased daily?
Sorry if this is basic but I really don't know what's going on with the fingerprinting.

I think they take the biometric reading when you first activate the ticket and then use that reading each time you enter a park again.

FWIW - I don't know if it's really a fingerprint. My husband and I often "test" the machine, since our hands are about the same size. We switch tickets and still get in using our own finger.

I would imagine the reading is erased after the last park closes on the last day of your ticket validity.

I'm going with the kids and grandkids in March and I was wondering if we would have a problem if we inadvertently switched tix. Sounds like it's not a big deal. Thanks for the info.

I wouldn't switch adult and kids, as your hands are different sizes Like I said, my husband and I switch all the time and never had an issue.

Can you use a marker to put initials or something like that on them? Maybe just label them 'kid' or 'adult?'

They're already marked. If you're staying at a Disney hotel, your admissions will be put on your room key - and those have names on them.

If you just buy regular admissions, I'm not sure if you're name is on it or not, but they will say adult or child on the back. If you have multiple children, you can write their name on it - but I really don't think it's necessary - particularly if they're very young.

Please use your own tickets Was just in Disney last month and got stuck several times behind families who screwed up the entry, using the wrong ticket for the wrong family member. It backs up the line and is really frustrating for everyone.

Each person must insert the ticket and then place their finger (same finger for each entry) in the scanner. So much nicer when people do it right the first time

Have fun!

The finger swipe attaches biometric info permanently to your ticket so it can't be used by anyone else, or sold to other people at a discount.

Each ticket is matched to your fingerprint for the duration of the ticket (mine are annual). They don't use this for young children. They sometimes turn off the reader when they are busy in order to move the lines along faster.

Cheers,

What the machine does is take a 1/2" by 1/4" portion of your fingerprint and converts it into a three-digit code. When you put your ticket in and place your finger on the reader, it looks for the code. It's not a full print record, and there's about a one-in-a-thousand chance of it being duplicated. (Per a ticket FAQ on a Disney board written by someone who works there.)

The purpose is to keep people from selling partially or fully-used tickets to others (though it prevents any kind of use). Many tourists have been / are scammed by hawkers advertising "cheap Disney tickets" because you can't tell by looking at the ticket what is on the ticket. People shell out lots of money, show up, and find out the ticket is worthless.

Never mind.

It's only a 3 digit code? I knew it made a hash of the fingerprint, but I didn't realize it was that generic.