How to choose a marketing agency for accountants: settle your own plan before the busy season

An accountancy practice (an accounting firm, in the US) works to a calendar it did not write, but which calendar depends on the clients. In the UK, HMRC's guidance gives 11:59pm on 31 January 2027 as the deadline for submitting a 2025 to 2026 Self Assessment return online. For the return before that, HMRC counted 475,722 taxpayers who waited until the final day, 31 January 2026, to file. In the US, the IRS named 15 April 2026 as the federal filing date for tax year 2025 individual returns. Limited companies run to a different clock: annual accounts are due at Companies House nine months after the financial year ends, so that work arrives through the year, not in January. A practice growing its Self Assessment book has one hard date to work back from. A practice growing its company book has twelve softer ones, spread across its clients' year ends. That is why the choice of clients has to come before the choice of agency: it decides when the agency must start, and what it must have ready.

1. Decide which clients and services you want more of

Start with a written list. Name the client types you want more of and the services you want to sell them. A practice might choose sole traders and landlords on Self Assessment, owner-managed limited companies, or business clients in one sector. An agency cannot make this choice for you. It depends on your fees, your people and your appetite for the work. Test it against last year's books: list fees by client type and service, and see where your best clients sit.

The two halves of the calendar pull the list in different directions. Self Assessment clients need to be signed and onboarded well before January, so their campaigns end early and leave a gap. Company clients can start in any month, so their campaigns can run steadily, timed to the year ends you want. A new group is also coming: Making Tax Digital for Income Tax reaches sole traders with qualifying income above £30,000 from 6 April 2027, which gives them a reason to look for help on a date of their own. Decide whether you want them before the campaigns start.

Focus has evidence behind it, with limits. TaxDome's 2025 report is based on 350 or more US business decision-makers. In it, companies earning over $1 million were twice as likely as smaller businesses to hire a niche accountant. CPA Practice Advisor describes TaxDome as an accounting practice management platform. Weigh the survey as a vendor study of business clients, not individual filers. Hinge's 2017 study of over 500 professional services firms across all industry segments found fast-growing firms much more likely to target a highly specialised niche, which shows association, not cause. Hinge itself sells branding and marketing to professional services firms.

Your list becomes the searches an agency targets, the audiences it leaves out and the offers it tests. If you cannot write it yet, finish that decision first, on your own or with a freelance adviser, and delay the hire. Once it exists, put it into your agency brief.

2. Count the new work you can take, per service and per deadline

Ask each partner and manager how many new clients, and how much new fee income, you can take on before the next peak, and how many company clients you can absorb in each quarter. Write one number per service. Clients who sign in the last week before 31 January arrive just when your team has least time to onboard them. That number becomes a ceiling on spend for each service, and a campaign should pause the day its service is full.

3. Build one claims file before anyone writes copy

Your professional body's rules decide what the copy can say, and the firm carries the risk. Hiring an agency does not move the duty: ICAEW says the firm remains responsible for marketing or publicity carried out on its behalf. So collect everything an agency may say about you into one file, in four parts, with one partner named to approve every page and advert against it.

Claims come first. ICAEW's guidance says firms shall not make exaggerated claims for the services they offer, the qualifications they hold or the experience they have gained. ACCA's guidance factsheet asks that any advertisement be clearly recognisable as an advertisement. The AICPA Code treats promotion that creates false or unjustified expectations of favourable results as deceptive. These are professional-body codes and guidance, not statute, and you should treat them as yours even when an agency drafts the advert. List the services, experience and numbers you can prove.

Titles second, copied from your body's register or state board listing. For ICAEW member firms, ICAEW says qualifying as a member firm does not automatically mean a firm can use the description chartered accountants. In the US, state law can restrict the certified public accountant (CPA) title: California, for one, reserves it to people its Board has certified or authorised, and to registered firms. Directory listings and structured data should use the same exact wording.

Consent third. ICAEW says the firm and client relationship is confidential, so a testimonial without consent would be inappropriate. Keep a log of the clients who have agreed to be named or quoted, and build case studies and review requests only from it.

Fees and outreach last. On fees, ICAEW says any reference to fees or charging rates must be made with the greatest care not to mislead. In the US, practitioners before the IRS face a 30-day lock: under 31 CFR 10.30, published fee rates cannot be exceeded for at least 30 calendar days after the schedule was last published. On outreach, the same section requires any solicitation made by or on behalf of the practitioner to identify itself as one. Copies of direct mail and electronic communications, with the list of who received them, must be kept for at least 36 months from last use, so decide who holds them. In the UK, the ICO treats limited companies, LLPs and Scottish partnerships as corporate subscribers under PECR, and sole traders and other partnerships as individuals. For a practice selling to both, that splits one prospect list in two.

4. Find out where your clients come from today

Without a baseline you cannot read the agency's results. For your last twenty new clients, record how each one found you. Add a "how did you hear about us" question to your enquiry form and phone script. Two sources point at referral. A 2015 study that HMRC commissioned looked at small and mid-sized businesses' use of tax agents. It found that most had selected, or would select, a new agent on recommendation from professional contacts, family or friends. A 2025 TaxDome survey of US business clients, reported by CPA Practice Advisor, put peer recommendation at 58 percent and online search at 17 percent. One is from 2015 and the other comes from a vendor. Use them to ask the question, not to answer it. With the baseline in place, no agency can be credited with clients your referrers sent.

What to ask once you are ready

With your side prepared, the questions can be short. A specialist agency may already know these deadlines and a generalist can learn them, so judge each by its answers, not its label.

1. Which of my client types would you go after first, and which would you leave alone? An answer built from your list and your fee data shows it has read your material; a generic channel mix shows it has not.

2. How will you time Self Assessment campaigns against 31 January or 15 April, and how differently will you run company work whose year ends are spread across the calendar? You want two plans, not one.

3. Will each report split enquiries by client type and trace each new client to its recorded source, so a referred client never counts as a paid win? Ask for a sample. Monthly is a sensible minimum, with a short note on what changed and why.

4. If enquiries come from client types outside my list, or keep arriving after a service has hit its capacity number, who tells me, how soon, and what changes first? Listen for a named trigger and a date for the next review.

5. Which pages and adverts need the named partner's sign-off against the claims file, and what turnaround will you allow in January? A fixed turnaround you can meet in your busiest month is the test.

Bear in mind who is giving this advice: The Social Target sells marketing to accounting firms, and its page on marketing for accountants and accounting firms is a sales page, not part of this checklist. The five questions work without it.

Three reviews after you sign

Fix all three review dates when you sign. If your list leans towards Self Assessment, put the 60-day review before Christmas, so any change lands before January.

At 30 days, check the claims file is in use. Every live page carries the named partner's sign-off, titles in directories and listings match the register wording, and the enquiry form asks for source, client type and, for a company, its year end, so new work can be slotted into the months your team has free.

At 60 days, check the mix. Sort the enquiry log against your written list: client types you named, ones you would take anyway, and ones you would turn away. If 31 January is close, check that Self Assessment spend has stopped at its capacity number while company campaigns carry on. If the turn-away group is the largest, ask what changes first and by when.

At 90 days, check fees by client type. Add up the annual fees signed so far for each type and set each total beside its capacity number, so you can see whether the book is moving towards the list or just growing. Then divide each paid channel's spend by the clients it alone brought in, leaving referrals out. Then choose: continue, change the mix, or stop.

When you have your client list, your capacity number and your claims list, tell us about your business and we will say whether we are the right fit for it.