If you are raising investment for your agency, you need a financial model. Not a set of management accounts. Not a three-year plan scribbled on a napkin. A real, working Excel model that an investor can stress-test.
Most agency founders skip this step or outsource it to someone who does not understand how agencies actually make money. The result is a model that looks pretty but falls apart when an investor asks: "What happens if your biggest retainer client leaves in month seven?"
This guide walks you through building an agency financial model from scratch in Excel. It is designed for a founder of a 10-to-50 person agency billing between £500k and £5m per year. The same structure works for smaller and larger agencies with minor adjustments.
We work exclusively with agency founders. We see these models every day. The good ones share a common structure. The bad ones share common mistakes. This guide gives you the structure and helps you avoid the mistakes.
Why Most Agency Financial Models Fail
Before you open Excel, understand why most models fail. It is rarely the maths. It is the assumptions.
A typical bad model assumes linear growth. Revenue goes up 20% every year. Costs go up 15%. Gross margin stays flat. No client churn. No seasonality. No delayed payments. The model shows a beautiful upward slope and the investor ignores it completely.
Investors have seen hundreds of these. They know the real world does not work that way. What they want is a model that reflects how your specific agency operates. That means modelling revenue by type (retainer vs project), headcount by role, utilisation rates, and cash collection cycles.
This is where agency finance fundamentals matter. The fundamentals are not complicated. They are specific. Revenue per head, utilisation, gross margin, and cash conversion. Get these right in your model and you have something worth presenting.
What You Need Before You Start
You need three things before you open Excel:
- 12-24 months of actual historical data from your accounting software (Xero, QuickBooks, FreeAgent). Monthly P&L, balance sheet, and cash flow if you have it.
- Your current headcount and salary data. Not just total payroll. Names, roles, salaries, and start dates for every employee and contractor.
- A clear understanding of your revenue mix. What percentage is retainer vs project vs one-off? Who are your top five clients and what do they pay?
If you do not have clean historical data, spend a weekend organising it. A model built on bad data is worse than no model at all. Investors will spot the inconsistencies within five minutes.
The Core Structure of an Agency Financial Model
A good agency financial model has five core tabs. You can add complexity later, but start with these:
- Inputs, all assumptions in one place
- Revenue, monthly revenue forecast by type
- Costs, payroll, freelancers, overheads, and cost of sales
- Cash flow, monthly cash movements including VAT and corporation tax
- Outputs, summary dashboard with KPIs and charts
Do not merge these into one sheet. Keep them separate. It makes the model easier to audit and easier for an investor to follow.
Tab 1: Inputs
Every assumption goes here. No hard-coded numbers anywhere else in the model. If an investor wants to change the utilisation rate from 70% to 65%, they click one cell.
Your inputs tab should include:
- Headcount plan by role (creative, strategy, account management, production, support)
- Average salary by role, including employer NI at 15% and pension contributions
- Utilisation rate (billable hours divided by total available hours)
- Average billable rate by role
- Retainer growth rate and churn rate
- Project pipeline conversion rate
- Payment terms (net 30, net 60, net 90)
- Overhead costs (rent, software, subscriptions, travel, professional fees)
- Tax rates (corporation tax, VAT, dividend tax)
Be realistic with your utilisation rate. A healthy agency runs at 65-75% utilisation. If you model 85% utilisation for a creative agency, an investor will assume you have never run an agency. They are right.
Tab 2: Revenue
Model revenue in two streams: retainer and project. Do not lump them together. They behave differently and investors know this.
Retainer revenue is predictable. Model it as a monthly recurring number with a churn rate. If you have 10 retainers at £5,000 per month and 2% monthly churn, your retainer book shrinks by one client every five months unless you replace them. Model the replacement separately.
Project revenue is lumpier. Model it based on your pipeline. Take your average project value (say £24,700) and your conversion rate from proposal to signed (say 35%). Then apply a probability-weighted forecast. Do not model every project you hope to win. Model the ones in your pipeline with a realistic conversion rate.
If you have a 12-person digital agency billing £800k per year, your revenue tab should show exactly where that £800k comes from. Client by client if you are small. Service line by service line if you are larger.
Tab 3: Costs
Costs break into three categories in an agency model:
- Direct costs, salaries and freelancers for billable roles. These move with revenue.
- Overheads, rent, software, insurance, legal, accounting. These are relatively fixed.
- Sales and marketing, business development salaries, advertising, events. These should be modelled as a percentage of revenue or as a fixed headcount plan.
Model headcount growth explicitly. Do not use a percentage of revenue. If you plan to hire two midweight creatives in month six and a senior account director in month nine, put those rows in. Investors want to see that you understand the timing of hiring and the lag between hiring and billing.
Include employer NI and pension contributions in your salary calculations. A £45,000 salary actually costs around £53,100 once you add employer NI at 15% and a 3% pension contribution. Model the real cost, not the headline salary.