X-post from Samsung: Confirmed working Telus SIM says Unregistered SIM in Koodo S3
 

I broke my Telus S3 (I747M), bought a used Koodo S3 (I747M), tossed my Telus SIM into it and it says "unregistered SIM". My work phone is the same make/model but with Rogers, when I put the Telus SIM in it it prompts for unlock code. I put the Rogers SIM into the used Koodo phone and it prompts for...

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