| Subject | English | Spanish |
| IMF. | opt back in | ejercer la opción de reintegro |
| fin. | to opt back in | optar por volver a recibir |
| comp., MS | opt in | participar (To explicitly consent to participate. Typically used in marketing programs and offerings, whereby an action (such as the use of personal information beyond the original, primary purpose for which it was collected) is not undertaken unless an individual explicitly consents. An element of choice) |
| fin. | opt-in | regla de aceptación (overdraft rule) |
| fin. | opt-in | optar por sobregiros (overdraft rule) |
| fin. | opt-in | optar |
| fin. | opt-in | aceptar |
| gen. | opt-in | opción de participación |
| gen. | opting-in | participación voluntaria |
| med. | opting-in system | consentimiento expreso |