If you do not collect consent at the same time that money is collected, feel free to set up a specific consent with regards to the trip within consents.
To complete this, select Students > Parent & guardians > parental consents > Add > name your consent type. If you select the checkbox here, all students will be included in this consent requirement. Do not select this box to only request consent for specific students. If left unticked, you can click back into the consent you have created and add the students you wish. You will then use your 'Trips' section to monitor payments and 'Consents' to monitor parental consent. You do need to keep both areas maintained.
Note: If you do choose to record consent separately, please be aware that these will need to be maintained separately and will not automatically update when a participant is added to the trip.