sprint unlocked my samsung galaxy note 3 and att gave a sim but phone is not recongizing sim card

[rybell]

I used and bought my -phone with sprint and my daughter has at&t she needs a phone At&t said it is compatible because it does use a sim card, sprint has already unlocked it however phone says invalid sim, is there another reason why its not working.

 

[Reynod]

Hmm ... try another SIM from another fone ... but first clean the sim using an eraser on the little gold contacts.