How to write a client report for a marketing agency

Most agency client reports have the same problem: they show what happened but don't explain what it means. Clients receive a table of numbers, aren't sure whether to be pleased or concerned, and file the report unread. Here's exactly how to write a monthly report that clients actually engage with — and that makes your agency look elite.

The 6-section structure

A well-structured agency client report follows a consistent flow that takes the client from "what happened overall?" to "what are you doing about it?" in six sections:

Section 1: Executive summary

2–3 sentences. The most important section. Leads with the headline result, acknowledges the most significant movement (positive or negative), and signals what's changing next month. This is the section most clients read exclusively — everything else is supporting evidence for people who want to dig deeper.

Bad: "This report covers performance for the month of March."

Good: "March was a strong month — organic traffic was up 22% year-on-year, driven by the content sprint we ran in Q1. Google Ads CPA came in at £38 against a £45 target, the best CPA in four months. The one watch area is Meta CPM, which rose 18% — we're refreshing creative in April to address this."

Section 2: KPI callout

A visual block showing the client's primary KPI targets vs actuals. For most agencies, this is CPA (cost per acquisition) and/or ROAS (return on ad spend). Show actual vs target with green (on/ahead of target) or red (behind target) colouring. This single block answers the question every client is silently asking — "did we hit the goal?" — in 3 seconds without reading anything.

Section 3: Website performance (GA4)

Sessions, active users, engagement rate, average session duration. Traffic by channel. Top landing pages. Year-over-year comparison for sessions and users. Keep this section to one page. The purpose is to show whether the website is healthy and whether overall digital footprint is growing.

Section 4: Paid performance (Google Ads and/or Meta)

Spend, clicks, impressions, CTR, CPA, conversions. Campaign breakdown (top 3–5 by spend). This is the section clients scrutinise most closely — they're paying for this directly and want to know whether it's working. Include the KPI callout for paid channels here (or link back to Section 2).

Section 5: Organic/other channels

Search Console data (clicks, impressions, average position, top 10 queries) if you run SEO. Social organic performance if relevant. Only include channels the agency actively manages — don't pad the report with data you're not responsible for.

Section 6: Insights and next steps

3–5 bullet points covering: what went well, what needs attention, and what's changing next month. This section transforms a backward-looking data review into a forward-looking management summary. Clients who read this section feel confident the agency is on top of things and actively managing their account.

How to write the executive summary

The formula: headline result → supporting context → watch area or forward signal.

Start with the most important outcome. Not the most complex — the most important. Usually: were conversions up or down, was CPA above or below target, was traffic growing or declining? One sentence for the headline.

Add supporting context. Why did it happen? What campaign or external factor drove the result? One sentence.

Close with a forward signal or watch area. What's changing, what are you watching, what's coming in the next period? One sentence.

The entire executive summary should be readable in 20 seconds. If it takes longer, it's too long. This is the one section where you must resist the temptation to include everything — you're writing a headline, not a summary of the entire report.

How to explain data to non-technical clients

The biggest mistake agencies make is writing for each other, not for clients. "Engagement rate increased 4.2 percentage points to 64.8% following optimisation of the campaign exclusion lists" is accurate but useless to a client who sells luxury candles.

The rule: every metric needs a so-what. Not just what the number is — what it means for the client's business.

• Don't say: "Sessions were 4,210 (+12% MoM)" → Say: "12% more people visited your website this month than last month."
• Don't say: "CPA decreased to £38 (-15% MoM)" → Say: "Each new enquiry cost £38 — 15% cheaper than last month and well ahead of your £45 target."
• Don't say: "Engagement rate was 64%" → Say: "64% of visitors who came to the site spent meaningful time browsing — a sign the paid campaigns are attracting relevant people, not just clicks."

Plain language isn't dumbing down — it's respecting the client's time. They hired you because you're the expert. Your job is to translate, not to demonstrate vocabulary. For the full structure of what to include in each section, see the digital marketing report template guide.

How long should a client report be?

For most agencies: 6–8 pages for a full-service client. 3–4 pages for a single-channel client (e.g., Google Ads only). Longer than this and clients don't read it. Shorter and it looks thin.

The test: if a client forwards your report to their CFO or MD and says "here's last month's results," does the report answer every question they'll ask without a follow-up call? If yes — it's the right length. If it leaves obvious questions unanswered — it's too short. If it takes more than 5 minutes to read — it's too long.

The AI-assisted writing approach

Writing the narrative for 10+ clients every month is one of the most time-consuming parts of agency life. AI changes this. Tools like Breut feed Claude the performance data plus a stored client brief and KPI targets — and Claude writes the executive summary and insights section in 3 seconds, personalised to each client.

The output isn't generic. Because the AI has context about the client's business, targets, and previous performance, it produces commentary that reads like a senior account manager who knows the account wrote it. Account managers review and edit (usually minor tweaks), approve, and send. Writing time: 2 minutes per client instead of 45.