In order to use someone else’s character for activity rolls or breeding, you must acquire Leasing Permissions.  The character owner must comment on this page with the following form filled out:

Character: (link to Masterlist entry)
Leasing to: @ username of person you are leasing to
Purpose for Leasing: (Example: 3 rolls; 3 breedings | Limit of 10 Slots)
Conditions: (Examples: must have Rider, must follow personality, must not participate in dangerous activities, must include courtship art, courtship art not allowed, etc.)
Rules:

Leasing Rules:

• Leased characters will have base activity rolls done for the Leaser.
• Leasing permissions cannot be retracted.
• If a character is leased, it should say so in the deviation description (to avoid accidental turn ins by the leasee).
• Only the owner of the character may lease out that character.
• Familiars are rolled for the person leasing, alongside the loot and events in activity rolls.
• You can’t place restrictions on what can and can’t be found from activity leases. This includes: RNG bonuses from Master Crafters, a Pink Fairy Armadillo finding an egg, dropping X item that the leasee really wants, etc. If you decide to make these deals in private, you won’t be penalized, but the group cannot enforce the deal.
• You may only limit slots in the following ways: Limit it to a split use, Limit reselling or trading, Make the owner tag you when it is used, Require or ban the attachment of courtship art. Any other restrictions must have you as a participant in a split and will count as one of your splits for the month.