I had postpaid T mobile connection (part of family plan) and I wanted to shift to the prepaid one (T mobile connect 15$/mo) as it was cheaper for me.

I called up T mobile customer care, they asked for the
(1) family plan account #, and
(2) the account pin
(3) a new sim card (this one from amazon)

I just had the account # and told them the name and cell no. of the family plan head, so they called him up and got authorization to drop me from the family plan.

They then transferred me to their prepaid division, they asked me for the Sim # (not the cell phone no.) that is written on the back of the sim cards purchased from amazon. Then they just transferred/ported my old no. from postpaid (family-plan) to my individual pre-paid plan. After, the phone got disconnected with customer care (as the old sim now became defunct). I replaced my old sim with my new sim (but with old cell #).

Even though they said that it will take 24-48 hours for my new sim to be activated, it got activated in 5 minutes and I received welcome texts from T-mobile. Could not be happier! It was no hassle at all.

Additionally, T-mobile gave me 1 month of free usage in prepaid. It has been almost 1 month that I saving around 10$/mo with this prepaid connection, I have faced no issues.

New to it

I called T-mobile to order service after receiving the SIMs. After getting all my info, running credit, etc, they took the two SIM #'s and tried to submit the order to start service. They were unable to process the order, they tried twice. Any additional failure would have invalidated the whole order. The only way for us to complete it was to order their overpriced SIMs and have them ship them. So we did, and I initially planned to return these.

I later got onto T-mobile's chat support, who initially stated they cannot activate SIMs purchased from Amazon as they're probably pre-paid sims. I said the listing states that they are compatible with post-paid, can you please check into exactly what the issue with these are, so I can report it accurately so other people don't run into this same problem.

After some time, the rep came back and said "good news, we can actually activate them!" and did. So now the sims actually work on my postpaid account, but it took a lot of elbow grease. And I still have to return their overpriced SIMs when they get here.

I'm still giving this 5 stars as I am 100% satisfied in that it greatly reduced a BS fee that I shouldn't have to pay so much for. But be prepared that it may come with some grief from T-mobile.

The T-Mobile website said both of these SIM cards were invalid, but I was able to activate a new pre-paid hotspot account successfully on my iPad using the activation wizard in the Apple/iPad Settings app. I'm not sure if this is an issue with T-Mobile or these specific cards.

Otherwise, some uninformed tmobile rep will probably tell you that the card has activation problems. For example, I was told by one rep that the card had already been activated, while another rep told me that I could not use these cards on a prepaid line. Bottom line is that only the TMobile Prepaid Customer Service reps seem to actually know what to do with this card. I am pleased that this card worked for me. I was porting an existing tracphone line to a Connect tmobile prepaid line.