If you have a Smasung Galaxy S8 (Standard Addition) Or S8+ be weary of cellualrphone unlocking companies like Cellunlocker, I was told by my Caries Verizon Wireless as well as Samsung electronics US division to seek out a third party unlocking service such as the one in the link above.
I was lucky that they were honest and admitted to being unable to assist mer=e in unlocking my S8+. But other might not be so lucky.