tl;dr; Postpaid costs more because of the fees/taxes. Need to see if that could cover the cost for roaming in the end.

So I was psyched about the T-Mobile’s Uncarrier move and the new Simple Choice plan with unlimited (128kbps) global roaming, especially since it was announced the day before we get a new iPhone 5s.

Now we have iPhone 5s and Nexus 4, both unlocked. About time to do some math.

Previously

with iPhone 4S under 2 year contract with AT&T.

• AT&T: $59+$10 (fees/taxes): 200MB, 200 SMS, no tether
• T-Mobile (prepaid): $30+$15: 5GB, tether
• Total: $114

  Current (temp)

We just broke the contract and are paying $100 termination fee. Current setup is temporary, to see how much the fee would look like. I keep my prepaid line for now.

• T-Mobile (postpaid): $50+$12 (fees/taxes): 500MB, tether, global roaming
• T-Mobile (prepaid): $30+$15: 5GB, tether, no roaming
• Total: $107

  Merging with T-Mobile postpaid

I was thinking of merging my prepaid to postpaid since it has Family Plan, and adding more lines (including tablets) make the base fee more affordable, which means:

• T-Mobile (postpaid 2 lines) $90 + $18 (fees/taxes): 500MB + 2.5GB, tether, global roaming
• Total: $108 That $18 fee/govt taxes are subtle but not something I can lightly dismiss. If we give up the roaming and go back to the plain prepaid:

2 Prepaid lines

• T-Mobile (prepaid) $30: 5GB, no tether
• T-Mobile (prepaid) $30+$15: 5GB, tether
• Total: $75 I absolutely support the Uncarrier move of T-Mobile, but $33/mo is a bit high premium.

So this leaves me the obvious question: whether $33/mo is worth for unlimited voice calls and global roaming. We rarely make phone calls these days, and 100 minutes included in the prepaid plan is more than enough.

I guess the roaming support would pay in the end if we make travels abroad every month, or at least once in two months, since buying a SIM would usually result in $30 or more ($50 in Canada for me), not to mention the wasted time looking for a phone shop.

Based on our number of trips this year, it would possibly cover the total cost in the end, but that might not be the same next year.

We have a plan to visit Europe and some Asian countries around Thanksgiving and Christmas, so we’ll see how valuable the roaming would be.

UPDATE: several readers commented that my fees/taxes are too high. This is because I currently live in San Francisco, where the city government taxes about $8 for 911 and “Utilities” (the bill from AT&T last month). In other cities, your charges will be much less.