Why Most Agency Founders Pick the Wrong Accountant
I see it every few months. A founder walks in, frustrated, having just switched from a general practice firm that "didn't get" their business. The accountant was perfectly competent for a plumber or a restaurant. But an agency? They didn't understand utilisation rates, retainer vs project revenue, or why a £200k profit with 40% gross margin tells a very different story to £200k profit with 65% gross margin.
When you choose an agency accountant, you are not just picking someone to file your CT600 and run payroll. You are picking a financial partner who should understand how your business actually makes money. That distinction matters.
Here are the questions to ask before you sign anything.
1. "How Many Agency Clients Do You Currently Work With?"
This is your first filter. A general practice accountant might have 200 clients but only 2 or 3 agencies. That is not enough exposure to understand the specific patterns agency businesses follow.
You want someone who works with at least 10-15 agencies. Ideally more. At Agency Founder Finance, we work exclusively with agency founders. That focus means we see the same patterns repeat across marketing, digital, creative, PR, and recruitment agencies. We know what a healthy retainer book looks like versus one that is about to unravel.
Ask for specifics. How many of their clients are agencies? What types? Do they work with agencies your size? A firm that handles a 50-person agency and a sole trader web designer will have a different perspective than one that only works with 5-15 person shops.
2. "What Is Your Experience With IR35?"
IR35 is not optional knowledge. If you use contractors, and most agencies do, your accountant needs to understand the off-payroll working rules inside out.
Ask them to explain the difference between inside IR35 and outside IR35. Ask how they handle Status Determination Statements (SDS). Ask what happens if HMRC challenges a determination you made using the CEST tool.
A good agency accountant will tell you that CEST is directional at best. They will explain that the Employment Status Manual provides better guidance for complex arrangements. They will know that your agency, as a medium or large business, is responsible for issuing SDS before the contractor starts work, not after.
If they look confused or say "we just leave that to the contractor's accountant," walk away. That answer will cost you money in back taxes and penalties.
Read our full guide on IR35 for agency contractors to understand what a competent accountant should be telling you.
3. "How Do You Help Agencies With Cash Flow Planning?"
Retainer income is predictable. Project income is not. A 12-person digital agency billing £800k per year with 60% retainer revenue has a very different cash flow profile to one where 80% comes from one-off projects.
Your accountant should ask about your revenue mix. They should want to see your management accounts, not just your year-end figures. They should understand that a big project win in January creates a VAT bill in March that needs to be planned for.
Ask how they help clients forecast cash flow. Do they recommend tools like Float or Spotlight Reporting? Do they review your monthly P&L and balance sheet, or just file your tax return once a year?
If the answer is "we do your year-end accounts and that's it," you are paying for compliance, not advice. That might be fine at £150 per month. But if you are paying £400+ per month, you should expect cash flow conversations as standard.
4. "What Is the Optimal Salary and Dividend Split for My Situation?"
Every agency founder should know the standard model: take a salary up to the primary NI threshold (£12,570 for 2026/27) and take the rest as dividends. But that is the starting point, not the answer.
The right answer depends on your profit level, whether you have other income, and your long-term plans. If you are a higher-rate taxpayer with £80k of profit, the optimal split is different from someone with £200k of profit who wants to extract every penny.
Ask your potential accountant to walk through the numbers for your specific situation. They should be able to tell you the dividend tax rates (10.75% basic, 35.75% higher, 39.35% additional) and the £500 dividend allowance without looking it up. They should know that the dividend allowance dropped from £2,000 to £1,000 to £500 over the last two tax years, and understand why that matters for your planning.
For more detail on this specific topic, see our guide on salary and dividends for agency founders.
5. "Do You Advise on Agency Structure?"
Most agency founders start as sole traders or single-director limited companies. That works fine until it doesn't. At some point, you might need to consider a holding company structure, especially if you plan to:
- Own multiple agencies under one group
- Bring in a co-founder or investor
- Extract profits tax-efficiently before an exit
- Protect intellectual property or brand assets
Ask your accountant if they have advised on holding company structures for agencies. Ask if they understand how to route dividends through a holding company to preserve BADR (Business Asset Disposal Relief) eligibility. Ask if they know that the 2-year holding period for BADR starts from the date you acquire the shares, not from incorporation.
A general accountant will say "you don't need a holding company yet." A good agency accountant will say "here is when you might need one, and here is what we would do when that time comes."
6. "How Do You Help Agencies Prepare for Exit?"
If you plan to sell your agency one day, your accountant needs to be thinking about that from year one, not year five. The decisions you make about profit extraction, asset ownership, and share structure in the early years can cost you tens of thousands in additional tax when you sell.
Ask your potential accountant about their experience with agency exits. Have they helped clients through a trade sale? Do they understand how earn-outs work? Can they explain the difference between a share sale and an asset sale from a tax perspective?
Ask specifically about BADR (Business Asset Disposal Relief). The lifetime limit is £1 million of gains at 18% CGT. To qualify, you must hold at least 5% of the shares and be an officer or employee of the company for at least 2 years before disposal. Your accountant should be able to tell you whether your current structure qualifies, and what changes might jeopardise that relief.
We cover this in more detail in our growth and exit planning articles.