Recording scope changes and billing extra work

How an accounting firm spots scope creep, records a change in writing against the engagement letter, and bills or absorbs the extra work with a record.

By Achekam · 11 October 2026 · 4 min read · For Accountants & audit firms in South Africa, Nigeria, Kenya

The engagement letter says annual financial statements and the income tax return. By March the firm has also reconciled three years of a loan account the client never understood, drafted a letter to the bank, sat in on a meeting with a potential investor and answered a stream of calls about a new branch. Each request was small. Together they doubled the work, and the fee in the letter has not moved.

That is scope creep, and it is rarely anyone's fault. Clients ask because the firm is helpful; staff say yes because the client is valued. The problem is not the extra work. It is extra work that nobody recorded, agreed or billed.

Spotting scope creep early

Scope creep is easiest to deal with while it is happening, when the client still remembers asking. It is hardest at billing time, when the client remembers only the fee they were quoted.

Signs worth acting on:

• requests that begin "while you're at it" or "quick question";
• a new entity, branch, system or funder the engagement letter does not mention;
• records arriving in a state the fee did not assume;
• staff booking time to an engagement under tasks the plan did not include.

The numbers show it too. Under WORK & DELIVERY > Hours: Allocated vs Consumed, staff can compare an engagement's planned hours with the hours logged. A job running ahead of its plan is often a job doing more than was agreed. Catching that during the work, rather than after, is covered in tracking audit hours against budget.

Scope variations are kept only in the browser

Achekam has a screen for logging scope variations under Billing & Finance. Know its limit before relying on it: variations logged there are kept only in the browser in which they were entered. They are not stored on the server, a colleague on another computer will not see them, and clearing the browser loses them.

Use that log, if at all, as a personal scratchpad. The firm's record of an agreed change in scope belongs in three places that last: the written variation to the engagement letter, the reason recorded against any WIP adjustment, and the client file.

A written variation to the engagement letter

The professional answer to a change in scope is a short written variation, signed or accepted by the client, before the extra work is done or at least before it is billed. It need not be long:

1. What the original engagement covered.
2. What the client has asked for in addition.
3. How the extra work will be charged: a fixed amount, by time, or included at no charge.
4. Any change to deadlines.
5. The client's acceptance.

For audits, the terms of the engagement are governed by ISA 210, which is part of the complete text of the standards in the IAASB's 2026 Handbook, alongside ISA 200, ISA 230, ISA 300 and the rest. Reviews and related services have their own standards in the same handbook.

AI can help with the wording. In Achekam, AI can draft a proposal's sections or an engagement letter's clauses, never the fees, and a person saves the draft. Achekam will not send one whose wording breaks the professional guardrails, or, for audits and reviews, before a partner has reviewed it. The partner still decides what the firm is agreeing to and at what price.

Billing the extra as a milestone

Once agreed, the extra work needs to reach an invoice. Treating it as a separate milestone keeps it visible and stops it disappearing into the general fee.

Staff can invoice a billing milestone from the engagement's own page, and Achekam refuses to invoice the same milestone twice. For a scope change, that means the agreed extra fee is invoiced once, when the extra work is done, clearly labelled so the client recognises it from the variation they accepted.

A worked example in words

A compilation client asks the firm to prepare a cash flow forecast for a bank application. It is outside the engagement letter. The manager sends a one-page variation stating the work, the fee and the date, and the client accepts it by e-mail. When the forecast is delivered, the manager invoices the agreed amount as a milestone from the engagement page, with the description used in the variation. At year-end, there is no argument about a fee that grew; the extra work has already been billed and paid.

Write-downs when the firm absorbs it

Sometimes the firm decides not to charge. The client is strategic, the request was genuinely small, or the firm's own planning missed something it should have seen. That is a legitimate decision, as long as it is recorded as one.

In the WIP Register, a partner, manager or administrator can write the related unbilled time down or off with a reason. Write-downs above the firm's threshold, 10% by default, and every write-off wait for approval by another partner. Write a reason that will mean something next year, such as "loan account reconciliations outside scope; absorbed this year; add to next year's letter".

Then act on it: if the extra work will recur, change next year's engagement letter and fee. Absorbing it once is a choice. Absorbing it every year is a pricing mistake, which fixed fees or billing by time helps to avoid.

At your next team meeting, agree the phrase staff use when a client asks for something new, such as "happy to, let me confirm the fee first", and the person who prepares the variation.

General guidance only, not advice on your own circumstances. Tax and payroll rules change: check the current position with the authority or your adviser.