There seems to be a lot of people asking this question so I thought I'd make a new topic so its easier to direct people to the info.
Kickstarter allows you to open an unlimited number of accounts and use the same card on all of them to make payment.
Here the quote of the inquiry to Kickstarter themselves:
I messaged them and they replied saying it shouldn't be a problem.
Kickstarter Support (Kickstarter)
Jul 8, 11:51 AM
Hi James,
You should be totally fine! Let us know if you need anything else.
Best,
Alfie
skilljim
Jul 8, 9:58 AM
Hi, I am a big Shenmue fan and have backed for the $1500 tier on this account. I also wanted to get the $80 tier so I would be able to receive both rewards, and I have backed this tier on a second account. I have backed it using the same debit card as I thought this would be okay, but I wanted to just double check before the project finishes that my card will be successfully charged twice, one for each of these 2 accounts. I needed to use 2 accounts, as it's not possible to back more than one unique reward tier, that the Shenmue 3 Kickstarter project happens to have.
Thank you for your time and help :)
James.
if you've already secured a physical version on a higher tier, open another account and get digital too. also digital is great as a gift to friends and family.
Please retweet the following or create your own to share this information on twitter. thank you
https://twitter.com/john_vivant/status/621990789510467584