The word "in-voice" refers to a document that lists the goods or services provided by a seller, along with the cost of these goods or services. When discussing antonyms for "in-voice," one might look for words that imply the opposite of a transaction or payment. Some possible antonyms could include words like disbursement, deduction, or rebate, which imply that money is flowing outwards rather than inwards. Additionally, words like deny or reject could be considered antonyms for "in-voice," as they imply that no payment or transaction is taking place at all. Ultimately, the antonym for "in-voice" will depend on the specific context in which the word is being used.