If you use a different name to pay for something like Netflix or Spotify, is that fraud?

Not if your intent is not to commit fraud. My given name is Judith but where I worked for 32 yrs I was called Julie because there were so many other Judy's working there. I then used the name Julie for everything, even banking accounts, except for my income tax returns and my driver's license. The credit agencies all show me as Judith but an also known as Julie. I stopped using the name Julie when I retired.

Just using a different name if you intend to commit fraud doesn't work unless you also change your SSN and other identifying information; e.g. date and place of birth.

i use whatever name comes in mind for on line applications, no one cares. i never use my own.as long as your bank info is correct no one cares about your name. if it is not your Netflix will not work

It sounds like what you're saying is that the account will be under someone else's name. They don't really care about that, as long as it gets paid. As long as the credit card is good, and they get their money, they're fine with it. Now if the account was past due, and they had to go after someone, that's a different story.

If you use a different name on your account, and you pay, that's not fraud.  If you use a different name fraudulently, like to get out of paying, that's fraud.

You don’t even exist.