Disclaimer: This guide is for the 4 most common scenarios people face and is not exhaustive. Let's begin! Okay let's clear some stuff up for everyone who is curious about how the ATT Next system works. Additional first note for all: if you are eligible for Next (see below), you pay NOTHING up front except for sales tax on the retail price of the phone. So for the entry level iPhone 6 aka $199 phone: Retail is +$450 on the full upgrade price, so retail would be $650. If you have 6% sales tax, then $650*6% = $39 tax. A. IF YOU HAVE A CURRENT 2 YR CONTRACT ON THE LINE YOU WANT TO UPGRADE: -- If you started the contract ON OR BEFORE JANUARY 18, 2014: You are eligible to upgrade to ATT Next on this line right now. This also applies if your contract is over. This will 1. End the remainder of your 2 year contract for this line, if any exists 2. Have NO ETFs for this line 3. Give you complete ownership of the device on this line that is now OUT of contract. Sell as you please and profit. -- If you started the contract AFTER JANUARY 18, 2014:You cannot upgrade to ATT Next until 20 months have passed on your 2 year contract. That is 1 Year, 8 months for anyone counting. So, if you signed up on January 19, 2014, you're looking at September 20, 2015. How unfortunate. This is the only real nitpick I have with ATT upgrade eligibility to the Next plan, as this is a long time to wait. Overview of ATT Next: -- You can either have the ATT 12 Month Plan or the ATT 18 Month Plan The way it works for current and future ATT Next lines is this: The 12 month plan is comprised of 20 payments, and the 18 month plan is comprised of 24 payments This is the cost of the phone (without tax) divided into 20 or 24 even parts over 20 or 24 months, depending on which plan (12 or 18) you have on this line. The 12 or 18 months refers to earliest upgrade period, so after 12 or 18 months, you can upgrade to a new phone without any money down (besides taxes on the new phone). B. IF YOU HAVE A CURRENT AT&T NEXT PLAN ON THE LINE YOU WANT TO UPGRADE AND HAVE MADE THE ONLY THE MINIMUM PAYMENTS (12 or 18 months' worth) At this point where you reach 12 or 18 months, you are required to trade in your phone to complete your eligibility for a new ATT Next upgrade. Everyone is whining about how the phone "isn't really yours". This is because you haven't paid it off yet! Remember how the 12 month plan has 20 months of payments and the 18 month plan has 24 months of payments? Well, after 12 months of payments on the former plan, you still have 8 payments left to make, so ATT is saying, "look, we will waive the last 8 payments if you trade the phone in". Say the payment is $32.50 (I will list general pricing per month below). You have paid 12 months * $32.50 = $390 and still owe 8 months * $32.50 = $260. Total cost is *gasp* $649! That sounds familiar! Yes, that is the retail price of a $199 iPhone, ladies and gentlemen. No ripoff here. If you wait until after you make your 20 payments (if you have the 12 month plan) or 24 payments (if you have the 18 month plan, you then own the phone. At this point, if you choose a new ATT Next phone for this line, you do not have to trade in your old device. Understood? Good. Moving on. Now, let's say - C. IF YOU HAVE A CURRENT AT&T NEXT PLAN ON THE LINE YOU WANT TO UPGRADE AND HAVE NOT YET MADE THE MINIMUM PAYMENTS (Less than the 12 or 18 months' worth, depending on your plan) You can log on to your ATT account via their website and use the options available to make some choices: PAY TO UPGRADE THIS DEVICE option. You will pay the remainder of your minimum monthly payments up to and including the 12th/18th month, which will immediately deem you "upgrade eligible". So, if you paid 10 months out of your 12, you will owe $32.50 * 2 months = $65.00. After that, you trade in your phone and proceed with a new upgrade as normal. PAY OFF THIS DEVICE option. Self explanatory. This is the remaining amount of money you owe on the phone (so it would be all payments through the 20th/24th month rather than 12th/18th month). If you made 10 payments on a 12 month Next plan and want to keep your current phone but also upgrade, then you will owe 20 months - 10 months = 10 months * $32.50 = $325.00. You will then OWN the phone and can proceed with a new ATT Next upgrade without trading it in. D. IF YOU HAVE A CURRENT AT&T NEXT PLAN ON THE LINE YOU WANT TO UPGRADE AND HAVE MADE THE MINIMUM PAYMENTS BUT HAVE NOT PAID OFF THE PHONE (More than 12/18 but less than 20/24 months, depending on your plan) You can either 1. Surrender your phone and upgrade. You made an extra few payments of $32.50 that you won't get back. Oh well. 2. Make the remaining payments via the website with the PAY OFF THIS DEVICE option: If you made 18 payments on a 12 month Next plan and want to keep your current phone but also upgrade, then you will owe 20 months - 18 months = 2 months * $32.50 = $65.00. You will then OWN the phone and can proceed with a new ATT Next upgrade without trading it in. The $32.50 I keep referencing, again, is for a '$199' phone, i.e. the entry level iPhone 6 with a retail cost of $649.00. Remember 649/32.50 = 19.999 aka 20. So, here we go with pricing: ATT Next 12 Month Plan (12 months of payments to trade in, 20 months of payments to own): 16 GB iPhone 6: $32.50/mo 64 GB iPhone 6: $37.50/mo 128 GB iPhone 6: $42.50/mo 16 GB iPhone 6 Plus: $37.50/mo 64 GB iPhone 6 Plus: $42.50/mo 128 GB iPhone 6 Plus: $47.50/mo The ATT 18 numbers aren't quite as exact a science as the 12, but these are pulled from ATT and are valid: ATT Next 18 month Plan (18 months of payments to trade in, 24 months of payments to own): 16 GB iPhone 6: $27.09/mo 64 GB iPhone 6: $31.25/mo 128 GB iPhone 6: $35.42/mo 16 GB iPhone 6 Plus: $31.25/mo 64 GB iPhone 6 Plus: $35.42/mo 128 GB iPhone 6 Plus: $39.59/mo Now, all of this is just for the cost of the phone alone. It does not include service costs, which are separate and are beyond the scope of this discussion. You can save some serious coin with ATT Next and Mobile Share though, (on the tune of $15/month per line for 6-9.99 gb and $25/month per line for 10gb and greater). Cheers!