Display the 'whole code' on your home or classroom wall. A5 glossy card, each show the explicitly taught grapho-phonemic correspondences on the outside but all legitimate letter sound correspondences are on the inside. These are the univerally acceptable correspondences, and align with the IPA. Even if children have different accents, refer back to these - and discuss phonology, etymology, morphology etc.  

These are displayed to align with the explicit teaching order of the alphabetic code, as seen in the 4 SSP Code Levels and chant strips. ie s a t p i n m d g ...