An agent with no owner

Short answer. An agent with no owner can still hold attributed spend. On Agents & allocation, open the agent and choose a person under Owner. Clearing an owner is not available once one is set.

What is missing

Attribution answers "which agent." The owner answers "who is accountable." Dashboard can show the agent and a dollar amount while Owner is empty. That is not unattributed spend. Unattributed spend has no agent. This spend has an agent and no person.

Name the owner

Open Agents & allocation and the Agents tab. Add agent says "Name + department. Owner defaults to you ({email})." A new agent starts with you as the owner.

On an agent that already exists, edit Name, Department, and Owner. The note is "Leave department blank to keep the current value. Choose a person as owner. Clearing either is not available." The owner list is people on Team. If the person is not a member, invite them from Team first. An invitation lasts 7 days. While a row says waiting to accept, do not send a second invitation for the same email.

Seat CSV rows use the department column on the file. The department on the agent is a separate field. An owner does not replace either one.

Before close

A locked chargeback month keeps unallocated dollars on unallocated (suspense). Naming the owner after the lock shows the change as an adjustment on a later draft. Name the owner while the month is open.

Team will not remove the only organization owner. The label is Last owner. That organization owner is not the same field as an agent's owner. Invite another organization owner before you change the last one.