Registration & Account Management

I'm trying to log in, but I'm being told my email or password is invalid. What do I do?
Can I order for more than one person through my Store Account?
How do I deactivate my account?
Why am I being asked to declare if I am buying for myself or someone else? What does that mean?
I created an account, but it doesn't show my order history. What do I do?
I no longer have access to the email I used to create my account. How can I reset my password?
Why am I being asked to register an account to place an order?
How do I change the email address I use to login to my account?
How do I reset my password?
I already have a Dexcom account set up. Can I use that to log in to the Store?