On December 24, 2021, the Mexican government announced that the issuance of the Digital Tax Receipt (CFDI) with the Complemento Carta Porte (Complemento Waybill or CCP) for foreign trade operations is mandatory for all modes of transportation effective January 1, 2022, but a transition period will extend through March 31, 2022. The CCP supports the movement of goods within Mexico and provides temporary legal custody to carriers.
The notice can be found here:
https://www.gob.mx/sat/prensa/el-sat-informa-que-habra-un-periodo-de-transicion-para-emitir-correctamente-la-factura-concomplemento-carta-porte-sinmultasysanciones84-2021?idiom=es