In paper writing you do not have to make the 0 (zero) and O (letter O) look different at all. Or you may add a slash across the zero in order to show the difference.
ɪ n WORD_BOUNDARY p eɪ p ə ɹ WORD_BOUNDARY ɹ aɪ t ɪ ŋ WORD_BOUNDARY j uː WORD_BOUNDARY d uː n ɑ t WORD_BOUNDARY h æ v WORD_BOUNDARY t ə WORD_BOUNDARY m eɪ k WORD_BOUNDARY ð ə WORD_BOUNDARY z iə ɹ oʊ WORD_BOUNDARY z iə ɹ oʊ WORD_BOUNDARY æ n d WORD_BOUNDARY oʊ WORD_BOUNDARY l ɛ t ə ɹ ɹ WORD_BOUNDARY oʊ WORD_BOUNDARY l ʊ k WORD_BOUNDARY d ɪ f ɹ ə n t WORD_BOUNDARY æ t WORD_BOUNDARY ɔ l WORD_BOUNDARY ɔ ɹ WORD_BOUNDARY j uː WORD_BOUNDARY m eɪ WORD_BOUNDARY æ d WORD_BOUNDARY ʌ WORD_BOUNDARY s l æ ʃ WORD_BOUNDARY ə k ɹ ɑ s WORD_BOUNDARY ð ə WORD_BOUNDARY z iə ɹ oʊ WORD_BOUNDARY ɪ n WORD_BOUNDARY ɔ ɹ d ə ɹ WORD_BOUNDARY t ə WORD_BOUNDARY ʃ oʊ WORD_BOUNDARY ð ə WORD_BOUNDARY d ɪ f ɹ ə n s WORD_BOUNDARY