Transactional sex refers to sexual relationships where the giving and/or receiving of gifts, money or other services is an important factor. The participants do not necessarily frame themselves in terms of prostitutes/clients, but often as girlfriends/boyfriends, or sugar babies/sugar daddies/mamas. Those offering sex may or may not feel affection for their partners.

Transactional sex is a superset of sex work, in that the exchange of monetary reward for sex includes a broader set of (usually non-marital) obligations that do not necessarily involve a predetermined payment or gift, but where there is a definite motivation to benefit materially from the sexual exchange.

Alcohol has been used as a currency for transactional sex in South Africa and Uganda.

This form of transactional sex is most commonly referred to as survival sex.

Cash remains to be the most common currency in transactional sex worldwide.

Since the 2018 passage of FOSTA-SESTA, up to a third of sex workers in the United States have turned into cryptocurrencies due to its anonymity, ability to avoid chargebacks, and being able to bypass banking platforms.