Abstract: In the sphere of communication in Sri Lanka using English fonts for recording Sinhala discourse during the use of Short Message Service or Interlingual Texting is very popular. Analyzing such discourse this study argues that the asymmetry in the phonologies of Sinhala and English, and the difficulty in graphically denoting of sounds of Sinhala in English make the deciphering of Interlingual texts complex leading to unintelligibility and ambiguity of the messages. Data analysis further identifies a formal vs. colloquial dichotomy in the register of interlingual texting. The nonvolitional and nonelective transfer of fossilized English loan phonology of Sinhala too is evidenced in the register. The spread of the language of Sinhala Interlingual texting to English print media too is noted in this sociolinguistic analysis.