Piotr properly slaps my wrist, saying,
[ʦ], as in tsar, rats lacks a corresponding IPA diagraph.
The voiced counterpart of [ʦ] is of course [ʣ]! These are IPA symbols for them. Even UniPad has both, though for practical reasons it doesn't provide ready-made symbols for all possible affricates: to transcribe retroflex [tʂ, dʐ], or lateral [tɬ, dɮ], you have to combine two characters. In most English realisations, [ts] is not close-knit enough to be a genuine affricate (like German z or Polish c); it's phonetically a stop + fricative cluster. However, in many British accents (such as Cockney) fortis /t/ is affricated rather than aspirated, and becomes a genuine (apical, alveolar) [ʦ], e.g. time ['ʦɒɪm].
Yes, Piotr. I make mistakes.
Another question. Few English words have ts initially, but ts final is usually grammatical. Should English transcriptions avoid the word-final digraph when the final s is a verb inflection or a plural? In my head, such an orthographic S would be mapped separately from the preceding orthographic T.
Umm. I'm asking, I think, if IPA transcription acknowledges such grammatical nicetities.