Sounds like a perfect candidate for a "Thanks for being part of our incredible journey, we have been acquired by ntrepnr! Isn't that awesome and wonderfully great! Oh, by the way, you have 7 days until we delete all your receipts." ;)
Why would you put important things like these in the butt? Why does one need an account? Why share receipts with a third party?
What is your exit strategy? Do you have export functionality already built? Where are the terms of service? Privacy policy? How is the project funded?