AT&T is announcing changes to its Mobile Share line of wireless plans today, rolling out a new "Mobile Share Value" structure on December 8th that offers subscribers a discount on service if they're not on a hardware contract. It's not as simple as a straight discount off the current plans, though; AT&T has actually tinkered with virtually every aspect of the Mobile Share pricing model. While many subscribers stand to see a modest price drop on their bill, some data buckets have actually gone up. Meanwhile, the company is standardizing its fee for each smartphone that you attach to a Mobile Share bucket — a flat $40 instead of the $30 to $50 it charges now, depending on bucket size. And notably, if the phone is off-contract, you buy it at full price, or you bring it to the network, you'll now pay $25 instead of $40.

A modestly better deal (except when it's not)

The hit will come to families who have three or more on-contract smartphones attached to a 6GB plan or larger — for these subscribers, the per-smartphone fee will be increasing by $5 to $10 per phone. For virtually everyone else currently using Mobile Share, the changes mean anything from a net zero difference to a fairly substantial savings depending on the data bucket, the number of phones attached, and whether they're on contract. Unsurprisingly, the most popular buckets for individuals — 1GB, 2GB, and 4GB — get the smallest discount; plans for on-contract phones will be no cheaper than they are today, while unsubsidized devices on those plans see a net discount of $15 per month.

Mobile Share Value can clearly be seen as a response to T-Mobile, which became the first US national carrier to effectively "discount" service plans by decoupling the cost of phones as a separate monthly payment. It can also be seen as something of a response to outrage following the rollout of AT&T Next, which double-dipped by charging customers a monthly fee for their phone while still building a subsidy charge into the cost of the service plan. Mobile Share Value doesn't meet T-Mobile's pricing — and it doesn't offer any discount at all for some customers — but it's mostly a better (if not convoluted) deal than the one it's replacing.

AT&T Next is getting a new option, too

As for AT&T Next, the carrier will be adding a new 18-month upgrade option, meaning customers can choose to trade in their phone every 18 months instead of the current 12 and pay a lower monthly fee for the phone, financed over 26 months instead of 20. Next qualifies for Mobile Share Value's lower plan pricing, but because you need to turn in your phone to upgrade, it's still not as good of a deal as simply paying full-price upfront or bringing a phone of your own — an option that certainly won't be affordable for all subscribers.

Existing customers will not be upgraded to Mobile Share Value automatically — they'll need to get in touch with AT&T on or after December 8th, when the plans take effect.