cash basis has no recorded synonym. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. Its one recorded opposite is accrual basis.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
a method of accounting in which each item is entered as payments are received or made
Synonyms, antonyms and the broader and narrower relations for cash basis come from Princeton University’s WordNet. Full sources and licences.