In a recent communiqué , the SAT confirmed that the mandatory use of CFDI 3.3 will be delayed until January 1, 2018. This means that version 3.2 can continue to be used until December 31, 2017.
The SAT acknowledges the scale of this change in modernization of the billing system for taxpayers, which is why it has issued this extension before finally rolling out the single definitive version in January 2018.
The notification also highlights other extensions regarding CFDI and some of its complements. Discover it on the CFDI website.