This question comes up right after explaining what a repetition really is and it is not easily answered.
Technically, once the first occurrence of a repeated segment has been translated and saved to the TM, all other occurrences of this segment will appear as 100% matches to the translator. So, they could be invoiced the same way as 100% matches.
BUT, depending on the type of text you have to translate or the language pair you deal with, this might not be the case. For example, a catalog that is translated into German might deal with “gearboxes”, where in German the singular and plural of this word are identical (Getriebe). This means not all occurrences of this segment (maybe the headings in a table) have to be translated in the same way. Or, taking German as a target language again, one and the same sentence in English can be translated in 3 different ways, depending on the gender of the object you are talking about. Example: Connect the one with the other. (Admittedly, that is not good style in English, but it happens 🙂 ). This sentence could have 3 different translations in German, depending on the gender of the thing you are talking about.
This also brings up the question whether a 100% match can be left unchecked (as many clients seem to think). It is a 100% match after all, so it was there before, it is in the TM, it has been translated and paid for already… The thing is, a 100% match only tells you that the SOURCE segment has appeared before. But it does not mean that the translation is a complete/correct or fits the context. That is why translation vendors usually will tell you that even 100% matches should be checked for correctness in context.
Spot on Angelika, especially as English is frequently the source, or pivot, language for a great deal of technical documentation translated into many other languages, and English is neutral for objects. Thus, very simple phrases like “Open it.” will certainly not be a repetition in other languages as the translation will vary according to the “it” referred to.