The paper presents the results of analysis of free phonemic variation in word phonemic structures in RP as its striking feature. Alternative pronunciation variants of words are created by vowels, consonants, and a combination of both when in free variation in a segmental composition of words. Free phonemic variation is conditioned by the position / phonetic environment of the alternating phoneme(s) in a word. The positional specification of free phonemic variation and the operation of a number of other factors substantiate the inner systemic character of free phoneme variation in the composition of English words in PR. EFL learners should be aware of existing alternative variants of words and their liability for change in the course of time.