'non-' originates from Latin, specifically the word 'non', where it meant 'not'. 'rebate' originates from Old French 'rabatre'/'rabattre' (to beat down, reduce), ultimately from verbs meaning 'to beat down' or 'bring down in price'.

'rebate' changed from Old French 'rabattre' (meaning 'to beat down' or 'reduce') into Middle English forms such as 'rebaten'/'rebate' with the sense of reducing or returning part of a payment, and eventually became the modern English word 'rebate'. The compound 'non-rebate' formed by adding Latin-derived prefix 'non-' to English 'rebate'.

Initially, 'rebate' had a sense related to 'beating down' or 'reducing'; over time it evolved to the financial sense of a deduction or returned payment. 'non-rebate' therefore developed its current meaning of 'not subject to that deduction/return'.