I believe it is lost due to the requirements not being kept
Hey skyee! This is a great question. I can definitely appreciate not wanting to lose your Promotional EIP bill credits. By and large, we try to prevent a problem for customers who want to branch out by having the credit follow the line (as long as the EIP is transferred as well) - but your best bet to be sure that this will happen with the particular promotion you're participating in is to Contact Us. Thanks for asking, and thanks for choosing to stick with T-Mobile!