Client handover in an agency: moving an account between account managers

The short answer

A good agency client handover passes five things to the new account manager: the current brief and scope, the history that explains it, the tone of the relationship, every open deliverable with its date, and the people on both sides. Then the outgoing manager introduces the new one to the client and stays reachable for a few weeks.

Agencies move clients between account managers for all sorts of reasons: promotion, a new hire, rebalancing workloads, someone leaving. The client sees it differently. To them, the person who understood their business has gone. A strong handover is how you keep that from turning into a lost account.

Why agency handovers are harder than they look

The scope and the contract are in a folder. The parts that keep a client happy are not:

• The history. Why the logo is that shade of blue. Why the client hates the word “synergy”. What went wrong in last year’s campaign and what you promised to do differently.
• The tone. Whether the client wants a weekly call or a short email. Whether the marketing director likes being challenged or prefers options.
• The informal agreements. The extra round of revisions you gave “just this once”. The deadline you moved without changing the contract.

All of this lives in the outgoing manager’s head, their inbox and, more and more, their chats with Claude or ChatGPT where they wrote the briefs and prepared the meetings. When they leave the company rather than just the account, it can disappear completely; knowledge transfer when an employee leaves covers that case.

The handover pack: five parts

Add the files that matter: the approved brief, the latest brand guidelines, the current status report. Final versions only, each with a line saying what it is.

An example pack

Here is a short pack for a made-up client. James takes over the Nordlit account from Anna, who moves to a new business team.

CLIENT HANDOVER: Nordlit
From: Anna   To: James   Effective: Mon 2 Nov

Brief and scope
Retainer: content and social for Nordlit's spring launch.
Contract No. 2026-118. Paid media is out of scope.

History
- Last spring the launch slipped two weeks after late approvals.
  We agreed a fixed approval day (Wednesdays) to prevent it.
- Client rejected a playful tone in 2025. Keep it calm and factual.

Tone
Laura (marketing director) prefers a short written update on
Fridays and a call only when a decision is needed.

Open work
- Launch brief: approved, in launch-brief.pdf
- Kick-off with Nordlit: Fri 6 Nov. Agenda due Thu 5 Nov.
- Social calendar for November: draft, owner Tom, due Wed 11 Nov

People
- Laura Price, marketing director: approves everything
- Peter Holm, finance: invoices and budget
- Tom (our side): social, Rachel: contracts

Files
- launch-brief.pdf: approved brief
- brand-guidelines-2026.pdf: current version

James can run Friday’s update and the kick-off without calling Anna.

The introduction: three steps

The pack prepares the new manager. The introduction prepares the client.

1. Tell the client first, with a reason. Before anything changes, the outgoing manager explains the move and why the new person is a good fit. A reason the client can accept, such as “James has run three launches like yours”, does more than a long apology.
2. Meet together once. A short call with both managers and the client. The outgoing manager hands over in front of the client, which shows the transition is planned.
3. Stay reachable for a set time. Say until when the outgoing manager can still answer questions, and let the client know the new manager is the first contact from that day.

Risks in the first month

• The client tests the new manager. Expect a request that pushes on scope. The handover should say what is in and out, so the answer is consistent.
• A promise surfaces that nobody wrote down. Ask the outgoing manager directly: “Is there anything you agreed that is not in an email?”
• Deliverables fall between owners. Every open item needs one named owner on the day of the handover.
• The tone slips. The new manager writes the way they always do, and the client notices. The tone notes exist for this.

For the structure behind any written handover, see how to write a handover note people actually read. For a full project with budget, access and risks, use the project handover checklist.

Doing it in one sentence with Colle

If Anna prepared the account in Claude or ChatGPT, most of the pack is already in her chats. With Colle she says:

Her assistant finds James, writes the summary, records the facts (the contract number, the kick-off date, the open deadlines) and attaches the brief and the guidelines. James gets a notification straight away and accepts in one click. He asks his own assistant “what did I get?” and drafts Friday’s update with the full context. You can name up to five people in one sentence, so Tom, who owns the social calendar, can get the same handoff.

The summary, facts and files stay together in a case. If James later passes the account on, the handoff travels with its full history. If the kick-off date moves, the fact is updated and its history kept. Colle does not replace your project tool; tasks stay there. Colle carries the context between people. See how this works for agencies.

When you do not need Colle

If your agency keeps detailed client notes in one shared place, account managers rarely change, and nobody prepares client work in an AI assistant, the pack and the introduction above are enough. Sales teams moving accounts between reps face the same problem with a commercial twist; see the sales account handover checklist.