I am looking for the opposite of billable; the context would be "billable hours". A complete example sentence could be

Sorry boss, the work I did from 9 to 10 is "not billable".

While writing a program, I encountered the technical correct, but somewhat ugly billable_true/billable_false-pair.

I want to rename the first to "billable", since its truthiness is reflected in the code already. It just leaves me with a very unsatisfying "not_billable" as opposite. While not wrong, I am hoping to find a single word that encapsulates this concept of hours I spent working on something, but cannot or want not put on the bill for some reason.

For the record, I am not a native English speaker, but I cannot even find an antonym in my native language (German). The word I am looking for should be an English word, since all words in the program are English(ish/as far as possible).

I did a quick search through the following sites:

  • synonyms.com
  • thefreedictionary.com / thefreethesaurus.com
  • thesaurus.net
  • openthesaurus.de

I did not find any single word describing this concept. I do not mean "slack", because the time I want to categorize was spent working. It just should not end up on the bill presented to the client. The word could have almost any connotation, but it should not have be too colloquial. It should be something I could tell a coworker without getting fired or reprimanded.

So, what would be the (ideally single-word) opposite of "billable (time)"?


Just to clarify: The domain I want to use the word is timetracking in IT. We have some internal projects, events and such, which are tracked, but not billed, because there isn't any client. We also have in some client-projects aspects that we do not put on the bill (e.g. internal "sync" meetings that are not wanted/needed by the client). We track these short meetings, because it's work-time, but it is not something the client needs to pay for.

  • Comments are not for extended discussion; this conversation has been moved to chat.
    – tchrist
    Sep 8, 2019 at 17:30

4 Answers 4


"Non-billable" is the common term according to some brief research.

  • 7
    Please could you include that research? Aug 23, 2019 at 4:36
  • 8
    This is the term used at all of the companies I've worked for.
    – nnnnnn
    Aug 23, 2019 at 7:43
  • I would be curious of he research, nontheless, this fits my purpose the most. How I didn't make the step from "not billable" to "non-billable" is also beyond me... :-) Thanks!
    – kronn
    Aug 23, 2019 at 9:31
  • 1
    @kronn "not billable" and "non-billable are both correct, but in different circumstances. For example, "this is not a billable work code" and "this is a non-billable work code".
    – RonJohn
    Aug 23, 2019 at 12:45
  • Charges not billable are overhead.
    – LawrenceC
    Aug 23, 2019 at 23:11

As an alternative to the standard "non-billable" answer, there is a related concept of "direct" and "indirect" charges used in the contracting world. "Direct" charges are where hours worked are billed directly to the client (e.g. they get an invoice that says a developer worked on the task for 80 hours at X rate). "Indirect" charges are hours worked on generally internal company tasks (e.g. company training) that is paid out of the company's profit (i.e. the difference in what they pay you and what they charge the client).


My company (in the IT world) categorizes these as "overhead". We use this for company quarterly meetings, annual performance review meetings, time spent on recruitment or proposal writing, etc. "You may charge 1 hour to overhead for this meeting."

  • +1 not only for having a usable word, but having the same number of characters (a nice round 8). Aug 23, 2019 at 23:46

From a computer science perspective, the important distinction presumably is that you will be associating a payer (or payor) with each amount. With unbillable hours, there is no payer. So you could choose a word that emphasizes this: payerless, no_payer, without_payer. The last one would allow you to give billable hours the parallel label with_payer.

  • The link to a (potentially) paying party is made separately in this context. All hours are linked to a billing-account, which has a default-value of being billable or not. You can however override this billable-state for each entry. Therefore it is important to me to emphasize the intent to put in on the bill later, regardless of presence of a payer. I like, however the focus-shift. Sometimes a good word is not in front of you, but lying in the bucket next to it.
    – kronn
    Aug 27, 2019 at 6:53

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