Credit control work grows with the number of fees that have no payment arrangement behind them, not with the number of clients. Fifty new clients paying by direct debit add very little chasing, while fifty who pay when they get round to it add a job. Before you hire, it's worth raising the share of fees that collect themselves and handing routine follow-up to software, so your people spend their time on the conversations that need them.
In this article
The short version
- Credit control work grows with fees that have no payment arrangement, not with the number of clients.
- Clients on direct debit add monitoring, not chasing, so your hundredth costs about what your tenth did.
- Before hiring, move new and existing clients onto direct debit and automate matching and routine reminders.
- AI agents can carry routine follow-up within rules you set, with you reviewing what they hand back.
- Difficult conversations and decisions to stop acting stay with a person.
What grows when your client list grows
Two kinds of fee grow with a practice, and they behave very differently.
Fees with an arrangement behind them grow cheaply. A mandate signed at onboarding collects for years without anyone touching it, so your hundredth client on direct debit costs roughly what your tenth did. What you take on is monitoring: a cancelled mandate, a failed collection, a fee that's grown past what the client expected.
Fees without an arrangement grow in step with your list. Each one needs a decision about when to follow up, a message, a reply to read and a judgement about whether the client is slow or struggling. Ten a month fits into a Friday afternoon. Two hundred a month is somebody's job.
So for planning, the share of next year's fee notes that will already have a collection arranged when they're raised tells you more than the number of clients you expect.
Books do tend to settle over time. In Adfin's payment data, direct debit accounted for 36% of paid invoices in the first month of a billing relationship and 74% by months seven to twelve, while invoices paid whenever the client chose fell from 26% to 7%. It's one platform's data, mostly small businesses and practices billing recurring fees, so read it as a direction. The clients left paying by hand are often the ones who won't or can't use a mandate, so your manual pile tends to get smaller and harder, not bigger.
How each part of credit control scales
"Credit control" covers several jobs, and they don't grow at the same rate:
| Job | Does it grow with the client list? |
|---|---|
| Raising fee notes | Yes, but software can absorb almost all of it |
| Taking payment | Only for fees with no arrangement in place |
| Spotting failed or cancelled collections | Yes, slowly, as monitoring |
| Routine follow-up | Yes, one invoice and one client at a time |
| Difficult conversations | Slowly, since a small minority of clients cause most of them |
| Reconciliation | Yes, unless payments match to invoices automatically |
Your case for a hire mostly comes down to routine follow-up. If you're growing on mandates, most of the table falls to software and the difficult conversations grow slowly. If you're growing on fee notes that clients pay when they choose, follow-up grows with your list and someone has to do it, whether that's a new hire, an outsourced service or software. For a sense of scale, research for the Department for Business and Trade found that, among businesses spending staff time on chasing late payments, the average was 86 hours a year.
What to change before you hire
You can usually take a lot of the routine work out before anyone new joins:
- Put new clients on direct debit at onboarding, written into the engagement letter, so new fees join the side of the book that collects itself.
- Move existing clients across in batches, starting with retainer clients whose fees are predictable. If they already pay by direct debit through another provider and you have 10 or more mandates, they can move through the Bacs bulk change process without signing anything.
- Have payments matched to invoices automatically, including part payments and transfers with missing references, so reconciliation doesn't grow with volume.
- Automate the routine follow-up on whatever's left.
Adfin handles all four in one place. It collects by direct debit, card, pay by bank and bank transfer, matches every payment to its invoice with a two-way sync to Xero or QuickBooks, and chases over email, SMS and WhatsApp from your own email domain. Its AI Customer Agents decide when and how to contact each client based on how that client has paid before, within rules you set: which channels they can use, how persistent to be, what goes out without review and which cases come back to you.
What still needs a person
Some of credit control won't ever be routine: the client who rings to say they can't pay this quarter, a fee they think is too high, the decision to stop acting. CIOT and ATT leave ceasing to act for non-payment to your judgement, with reasonable notice to the client.
Supervising the software is a person's job too. The professional bodies' guidance on AI tools asks you to treat AI output as you would a less experienced colleague's work, reviewed with care, and says you stay accountable for it. In practice that means approving the templates and rules, dealing with the cases the agents hand back, and looking at the aged debtors list every month.
With the routine work handled, one person can usually keep on top of more clients. The headcount question then turns on how much judgement work your book produces, which tends to grow much more slowly than the client list.
Common questions
Does a growing practice need a dedicated credit controller? It depends on how many of your fees have a collection arranged. If most come out by direct debit, the work that grows is monitoring and the occasional difficult conversation, which one person can often absorb.
What makes the credit control workload grow? Fees with no arrangement behind them, each needing its own follow-up, plus exceptions on the arrangements you have. More clients on the same direct debit setup add very little.
Which credit control jobs grow as a practice grows? Routine follow-up on fees with no payment arrangement grows one invoice at a time. Collections under a mandate and payments matched automatically barely grow at all.
Should I outsource credit control or automate it? It's worth reducing the pile first by moving fees onto direct debit and automating routine reminders. What's left is smaller and harder, and you can then decide whether it needs a person in-house or outside.
Do clients have to re-sign if I move my mandates to a new provider? Not if you have 10 or more mandates; they move through the Bacs bulk change process. With fewer than 10, clients sign a new mandate.
How much time does chasing late payments take? Research for the Department for Business and Trade put it at an average of 86 hours a year for businesses that spend staff time chasing late payments.
Sources
- Department for Business and Trade / Office of the Small Business Commissioner - Late payments research: impact on the UK economy (accurate as of October 2026) https://assets.publishing.service.gov.uk/media/688a089a6478525675738ff9/late_payments_research_impact_on_uk_economy.pdf
- ATT - PCRT and the ethical use of artificial intelligence tools (accurate as of October 2026) https://www.att.org.uk/sites/default/files/2026-01/PCRT%20&%20ethical%20use%20of%20artificial%20intelligence%20tools%20%E2%80%93%20Jan%202026%20ATT.pdf
- CIOT - Professional Rules and Practice Guidelines (accurate as of October 2026) https://www.tax.org.uk/professional-rules-and-practice-guidelines
- Adfin - Credit control (accurate as of October 2026) https://www.adfin.com/credit-control
- Adfin - Next-generation direct debit (accurate as of October 2026) https://www.adfin.com/direct-debit-payments
