Here, in the first study of its kind, we examined the spelling of letter names by 30 school children (mean age 11 years; range 1012 years) and 24 adults (mean age 23 years; range 1955 years). While there is no single agreed-upon spelling for each letter of the English alphabet, it is possible to determine whether a spelling pattern is an acceptable approximation of a phonological pattern. We hypothesised that letter names which previous studies have shown to be difficult to process in early childhood when literacy instruction is just beginning (e.g. non-iconic letters such as H and W), might elicit a higher number of spelling variations and a higher number of unacceptable spellings in later childhood. We further hypothesised that, in adults, secure letter name knowledge and more sophisticated sound-spelling correspondence skills would result in reduced variation in spelling patterns and a reduced number of unacceptable spellings, overall. The results were in line with expectations. Some letter names appear to be inherently more difficult to process than others and this difficulty lingers beyond the earliest years of literacy instruction through to later childhood; although, it is reduced in adults.