Large traders often want the best execution desk and the cheapest clearing, which are rarely the same firm. A give-up agreement lets an executing broker hand the fill to the clearing fcm that holds the account, for a per-side fee.
For retail this shows up as an extra line item when using a third-party front-end or a prop platform that routes through one firm and clears at another.
Example: a fund's futures desk executes 200 lots through a bank's algo, then gives them up to its prime FCM. The bank charges $0.20 per side execution; the FCM charges clearing and exchange fees.
Related: fcm, clearing-house, exchange-fee, round-turn, introducing-broker