Hi @Sheila10, some Samsung devices do allow you to see if this is the case or not (but not all unfortunately).
Please see the below steps - use the Phone dialer:
For some select Samsung devices, dialing this code will show you if it’s network locked or not: *#7465625#
If your phone shows an a screen with these three items, check out the explanations below to know what each of them means:
[ ] Network lock
[ ] Subset lock
[ ] SP lock
If all three items are indicated as OFF, then your Samsung phone must be network unlocked.
If Network lock says ON, then your Samsung device is network locked.
If Subset lock is ON, then your Samsung device has to be unlocked and requires a code from the original carrier.
If SP lock is ON, then your Samsung device has to be unlocked and requires a code from the service provider. Some third party retail shops can provide you this code.
If nothing happens when you dial *#7465625# you can assume that your phone’s firmware does not allow the code, or its service menu has been disabled.
Many thanks
Tom_W