Takes 60-plus ad unit sizes and streamlines them to six.
The trade association first unveiled its plans in December, and now says version 2.0 of its ad package is complete.
The package makes it easier to create, buy and sell mobile ads for phones and tablets.
Ad networks and publishers have until the end of April to become compliant, after which they will be awarded compliance stamps for use on their websites and marketing materials.
MMA's global CEO Greg Stuart believes cutting down the formats will speed up adoption of mobile advertising. He said: “That simplicity frees brands and agencies to focus on developing innovative, compelling mobile campaigns that span the widest possible variety of devices and demographics.
"As a result, the new guidelines make it easier than ever to buy and sell ads for phones and tablets.”
To create the Universal Mobile Ad Package v.2.0, the MMA and ImServices Group, analysed hundreds of billions of mobile ad impressions delivered across the global mobile advertising marketplace in 2Q 2011.
MMA convened a 'swat' team to compile the guidelines, comprising AT&T Adworks, WDIG, ESPN Mobile, Google, InMobi, Joule, Jumptap, Medialets, Microsoft, Millennial Media, Ogilvy, Tribune, Turner and The Weather Channel.
The final standards are supported by the Newspaper Association of America, the Interactive Advertising Bureau and the buy side at global ad agencies.