Unless you need a SIM immediately, there's no reason to go into a T-Mobile store and pay $25 for one of these.

Works for prepaid or post paid plan. I use it because I travel out of the country and t-mobile is the only US carrier I can find that gives you free texting whilst out of the U.S.
the sim is able to be used in various sizes. I use micro for the iphone7.

T- mobile sells this same thing for $20 in the stores that I have been to.

This was the best product ever bought most other sim card gotten online never work but T-Mobile did I just switch over too the 30 dollar prepaid plan is one of best deal there are in prepaid service provider. T-Mobile provide me 100 mins unlimited text and 5 gig of data each month with binge on program allow me to watch unlimited Netflix and Youtube videos without using my data at all as well pandora for music streaming. As a student those service are require in me utilized everyday at school and home.

I'm already a T-mobile customer but bought an unlocked phone that required a nano sim card. T-mobile stores charge about $20 for this exact kit, so half price is a good deal. The sim card itself was a little difficult to punch out. It's not perforated well and obviously you don't want to use too much force and bent the card. But after several minutes of gentle pushing, I got it out. It was easy to call 611 and register the card to my phone line. Within about 15 minutes, my number was switched over and my new phone was operational.

UPDATE: T-Mobile just within the last month or so removed this plan, so this amazing plan is no longer available. Sorry for the bad news guys.

T- Mobile has a plan that's mostly a secret that I'm a huge fan of.

It's $30 prepaid and gives you unlimited texting, 5GB of 4G/LTE data (with reduced speeds after), and 100 talk minutes. That's awesome for me because I text a lot and use a fairly large amount of data between spotify in the car and internet when I'm not on WiFi. Only twice have I come close to using 5GB of data. I also don't talk on the phone much, and with an iPhone, calling other iPhones with facetime talk doesn't use your minutes. The other thing is that the plan has free international talk and text, so it was great for my French roommate to have for a few months while she stayed with us.

This card is your gateway to getting that plan. You find the plan online and you have to have your T-Mobile capable phone already (this plan doesn't work with phone payment plans), then you get this sim card, activate the sim card using this pack online, you set up your automatic payments, and you now have a $30 unlimited text and data with 100 minutes talk plan. You'll be hard-pressed to find anything close to that.

You have to do the whole process online though. T-Mobile doesn't sell these cards, they'll try to sell you a plan to get the sim card for $50 a month, then let you switch your plan. Save yourself time, money, and effort and just get this sim card pack online and activate the plan online.