Nope. Never had to. Even if the account I currently had was no longer available, I still never had to upgrade or change my account. I have voluntarily change my account to make more interest, but that was not because I had to, but because I wanted to.

What Elroy says about online/phone scams. Only ever do it in person at the bank.

Other than that, the reason to upgrade/downgrade is to avoid fees or get more services. For instance if you have a large IRA and your home mortgage with a bank, they will probably give you a free upgrade to a better checking account with no monthly fee, free cashiers checks, rewards debit card, stuff like that.

You can change your bank account at your local bank, or call them up. If someone is asking you to upgrade online, even if it looks like your official banking institution, DON'T. They are phishing and will try to get your personal banking information. They will identity theft you. Your bank doesn't do this kind of business online. GO SEE THEM IN PERSON. But never, ever ever fill out any forms, no matter how real (copied) they look or you are just handing your wallet, credit card, banking card, life over to the thieves.

upgrade it how? for what reason?