selling on an old phone I don’t want registered to me

A SIM do not dictate ownership on the iPhone. An Apple ID establishes ownership. If the iPhone is not signed into an Apple ID and has been returned to factory settings (preferably with a “Hello” screen when turned ON), then the iPhone will NOT be registered to your Apple ID.

You may erase the iPhone by using the following procedure 👉 What to do before you sell, give away, or trade in your iPhone or iPad - Apple Support

Axel F.

If you do not leave your Apple ID information, then there will be no access to your phone. You can also check in the settings which devices are connected to your Apple ID

..Sundaymail..

An iPhone or other device uses actual SIM card. Once it's removed

the device would naturally 'show Hello' on startup. As you are not

able to access that without SIM card. And it could also show SOS.

If you see No Service, Searching, or SOS on your iPhone or iPad - Apple Support

//support.apple.com/en-us/HT201415

If you see 'invalid SIM' or 'no SIM' on your iPhone or iPad - Apple Support

//support.apple.com/en-us/108914

..So long as no sim card is recognized, or no eSIM is set up on later

model iPhones, indicators would appear: no online access allowed..

.These links give some idea on when there's no remaining user data.

As a test subject, I've an iPhone 8; wiped and without a SIM card.

These details show as suggested, where they are applied, are true.

Links help. I've tons of bookmarks to Apple support articles..🍄🐝