An accounting firm does not earn a return merely because software produces a summary faster. Return appears when the firm converts reliable capacity into additional profitable engagements, lower overtime or contractor cost, avoided hiring, reduced rework or a service improvement the firm has chosen to value.
This guide provides a calculation method for accounting, bookkeeping and tax firms. All figures are illustrative, not Binarify client results or industry benchmarks. The firm’s finance, practice, technology and professional-standards owners should validate the inputs.
Choose one engagement unit
Define a recurring unit such as a monthly bookkeeping close, annual accounts job, tax return, payroll cycle or client onboarding. Split the data when service, entity complexity or client behaviour changes the work materially.
Record a representative baseline:
- engagements started and completed;
- staff time by preparation, review, correction and client chasing;
- elapsed time and work in progress by stage;
- missing-information delays and reminders;
- rework and quality-review findings;
- realisation, write-offs and contribution margin where available; and
- staff role and loaded cost for each activity.
Do not rely on timesheets alone when the firm knows they are incomplete. Combine system timestamps, a short time study, workflow states and a reviewed sample.
State how the benefit becomes financial
Write a testable chain. For example:
A controlled document register reduces staff chasing and file preparation. The practice uses the released capacity to accept 12 additional monthly bookkeeping clients without the planned contractor, while first-review completeness remains above the agreed threshold.
If the additional clients, contractor change or hiring decision is not credible, report capacity as an operational benefit. Do not multiply saved hours by a billing rate and call the result profit when the firm cannot sell or redeploy those hours.
Calculate realised capacity
Annual gross hours released
eligible annual engagements × measured minutes saved per engagement ÷ 60
Annual realised hours released
gross hours × adoption rate × workflow availability
Suppose a firm completes 1,800 eligible monthly-close engagements a year. A pilot reduces preparation by 22 minutes. Adoption is expected to reach 80%, and availability for supported cases is 95%.
1,800 × 22 ÷ 60 × 0.80 × 0.95 = 501.6 realised hours
The 501.6 hours remain capacity until the practice applies them to an evidenced action.
Convert capacity without double counting
| Benefit route | Evidence needed | Financial treatment |
|---|---|---|
| Additional client work | Demand, service capacity and contribution per engagement | Use contribution after delivery costs, not revenue |
| Overtime reduction | Paid overtime baseline and changed schedule | Count the actual reduction |
| Contractor reduction | Invoices, end date and replacement plan | Exclude spend already due to end |
| Hire avoided or deferred | Approved workforce plan and timing | Recognise from the date the cost would start |
| Rework avoided | Corrected items, time and loaded cost | Confirm the error was removed, not moved |
| Write-offs reduced | Historical write-off reason and changed process | Use observed change after rollout |
| Faster turnaround | Retention, pricing or cash-flow mechanism | Keep operational unless finance approves a value |
Do not add capacity value and additional-engagement profit when they use the same released hours. Assign each hour to one benefit route.
Model work in progress and deadlines
Use weekly arrivals and completions:
closing work in progress = opening work in progress + jobs started − jobs completed
Track work by stage and age. A faster preparation task may not improve turnaround if accountant review, client response or filing capacity is the actual constraint.
Include seasonal peaks. A tax workflow that performs well in a quiet month may fail when document volume, temporary staff and deadlines change together.
Include full ownership cost
Count:
- workflow mapping and control design;
- platform configuration and integration;
- data clean-up and template preparation;
- model, document-processing and hosting usage;
- security, privacy, professional-risk and supplier review;
- testing and representative file preparation;
- staff training and supervised adoption;
- human review and quality sampling;
- incident handling, monitoring and change approval; and
- internal product ownership and support.
Include existing platform features in the comparison. If Karbon, TaxDome, Xero, QuickBooks or another subscribed product already supplies the required workflow, configuration may have a better return and lower continuing risk than custom development.
Calculate ROI and payback
First-year net benefit
realised financial benefits − first-year incremental costs
First-year ROI
first-year net benefit ÷ first-year incremental costs × 100
Monthly payback point
The first month in which cumulative realised benefits exceed cumulative incremental costs.
Use a monthly table when implementation, adoption, seasonal volume and benefit realisation change over the year. Present conservative, expected and upside scenarios without combining every favourable assumption.
Binarify accounting AI value ledger
This proposed artifact makes each business-case claim auditable.
| Measure | Baseline source | Pilot comparison | Conversion action | Financial owner | Quality guardrail |
|---|---|---|---|---|---|
| Document-chasing minutes | Work logs and sample | Same service and client segment | Overtime, contractor or capacity plan | Practice manager and finance | Missing evidence at review |
| Preparation minutes | Time study and system events | Same complexity band | Additional work or hiring plan | Service-line owner | Accountant correction rate |
| First-review completeness | Quality sample | Blind reviewed sample | Rework cost avoided | Quality owner | Material omission rate |
| Engagement turnaround | Workflow timestamps | Same seasonal window | Approved retention or service value | Partner | Late or rushed review |
| Realisation and write-offs | Billing system | Same service definition | Observed margin change | Finance partner | Scope or quality complaints |
| Operating cost per job | Vendor and cloud bills | Observed supported volume | Direct cost deduction | Technology and finance | Availability and failed writes |
Reject any benefit row without a named source, owner and conversion action.
Keep professional quality as a release condition
Pair financial measures with:
- evidence completeness and provenance;
- incorrect classifications, matches and suggested treatments;
- accountant corrections and overrides;
- post-completion adjustments or amended filings;
- client complaints and confidentiality incidents;
- unsupported AI-generated sources or references;
- access, retention and failed-write events; and
- differences across supported client, language and document groups.
ACCA’s current AI risk guidance for practices stresses that firms cannot outsource professional judgement to technology. A pilot that saves time while weakening review evidence has failed its release condition.
Run a decision-grade pilot
Agree the eligible population, baseline and stop conditions before implementation. Run shadow mode on a representative set, then use a controlled assisted phase with named reviewers.
At the decision point, answer:
- Did the complete engagement improve, or did work move to the reviewer or client?
- Which released capacity has a funded or revenue-producing use?
- Did quality and confidentiality remain within the agreed limits?
- What will operation, review and future changes cost?
- Which cases are unsupported and how are they handled?
- Who owns benefit realisation, professional sign-off and rollback?
Apply the calculation to client document collection or bookkeeping exception and month-end review. Explore our AI consultancy for accounting firms, or book a 30-minute conversation to define one baseline.