Which firms provide outsourced controller services?
Outsourced Controller and Bookkeeping: The Firms The Shortlist Report Finds
3 firms lead, appearing in 20.5–27.6% of 210 AI responses. The sample cannot separate them, so we do not pretend it can.
Three firms lead
BPM, Etisson and AccountingDepartment.com come up most often here. They are close enough together that the order between them is not worth reading anything into.
BPM58 of 210
Provides fractional and interim controller services and broader outsourced accounting for mid-market companies with complex needs.
Etisson53 of 210
Provides outsourced controller services including month-end close, financial reporting, reconciliations, and budgeting, primarily for CPA firms.
AccountingDepartment.com43 of 210
Provides outsourced accounting, bookkeeping, controller support, and tax coordination for growth-stage companies roughly $2M–$50M revenue.
Based on 210 ChatGPT responses to this question, collected August 8, 2026–September 18, 2026. Firms are counted once per response. How we measure.
The ranking
| Firm | Responses | Share | |
|---|---|---|---|
| Tier 1 3 firms, 20.5–27.6% | |||
| BPMProvides fractional and interim controller services and broader outsourced accounting for mid-market companies with complex needs. | 58 of 210 | 27.6% | |
| Etissonetisson.comProvides outsourced controller services including month-end close, financial reporting, reconciliations, and budgeting, primarily for CPA firms. | 53 of 210 | 25.2% | |
| AccountingDepartment.comProvides outsourced accounting, bookkeeping, controller support, and tax coordination for growth-stage companies roughly $2M–$50M revenue. | 43 of 210 | 20.5% | |
| Tier 2 7 firms, 13.8–17.6% | |||
| Genpactgenpact.comHigh-volume finance and accounting outsourcing and transformation for large enterprises and global operations. | 37 of 210 | 17.6% | |
| Tristan CPAtristancpa.comOutsourced accounting, bookkeeping, and fractional Controller/CFO services for $1M–$10M businesses. | 36 of 210 | 17.1% | |
| Accountablyaccountably.comDelivers outsourced bookkeeping, reconciliations, month-end close, and reporting to SMBs and accounting firms. | 35 of 210 | 16.7% | |
| WNSProvides high-volume global finance and accounting outsourcing with analytics for large and mid-market organizations. | 34 of 210 | 16.2% | |
| Auxisauxis.comProvides nearshore dedicated teams for accounts payable, receivable, collections, and finance transformation. | 33 of 210 | 15.7% | |
| Accentureaccenture.comDelivers global finance transformation, outsourced accounting operations, and shared services for large enterprises. | 32 of 210 | 15.2% | |
| Adams BrownDelivers outsourced controllership and month-end close services through a CPA firm to SMBs and middle market. | 29 of 210 | 13.8% | |
Key findings
- BPM, Etisson and AccountingDepartment.com lead this sample, each named in 20.5–27.6% of 210 ChatGPT responses to the question “Which firms provide outsourced controller services?”, collected August 8, 2026–September 18, 2026.
- The gaps between BPM, Etisson and AccountingDepartment.com are inside the margin of error at 210 responses, so The Shortlist Report groups them in one tier rather than ranking them against each other.
- 10 firms cleared the reporting threshold on “Which firms provide outsourced controller services?” in ChatGPT as of September 18, 2026; the full table with response counts is below.
- BPM appears in 2 of the 13 fractional CFO and outsourced accounting firms reports published by The Shortlist Report, the widest coverage of any firm named on this page.
- No firm paid to appear in this ranking; placement cannot be bought, and the counts come from ChatGPT responses rather than from submissions.
Why the tiers fall where they do
Tier 1 holds BPM, Etisson and AccountingDepartment.com, named in 43 to 58 of the 210 ChatGPT responses. They are grouped rather than ranked because the gaps between them are inside the margin of error at this sample size — one extra mention would reorder them, so an order would be reporting noise as a finding.
Tier 2 holds Genpact, Tristan CPA, Accountably, WNS, Auxis, Accenture and Adams Brown, named in 29 to 37 of 210 responses (13.8–17.6%). The sample does separate these firms from the tier above: the difference from the leading group is larger than the margin of error, which is what puts them in a tier of their own.
The test is McNemar’s at 95%, applied against the same 210 responses for every firm. The full reasoning, and what happened when we ranked one-to-N instead.
What the sample shows
3 firms lead this question: BPM, Etisson and AccountingDepartment.com. They appear in 20.5–27.6% of the 210 responses. The gaps between them are inside the margin of error at this sample size, so they are listed together rather than ranked against each other.
658 firms were named at least once across the sample. 10 of them cleared the threshold of 2 responses and appear above; the rest were named once and are inside the noise.
How to read this
Firms are grouped into tiers, not ranked one to fifteen. A tier holds every firm whose 95% confidence interval overlaps the leader's, which is a long way of saying the sample cannot tell them apart. Order within a tier is arbitrary — read the counts, not the position.
Share is the percentage of responses that named the firm — not a quality score. A firm scoring low here may be excellent and simply under-written about online, which is a finding about its visibility rather than its work.
The same question was asked repeatedly because AI assistants do not answer identically twice. A single response would tell you almost nothing.
What this measurement does not tell you
- It is not a quality ranking. Share reflects how much has been written about a firm online, which is what an AI assistant reads. A capable firm nobody writes about scores low here.
- It is a reading from a date range, not a permanent standing. This sample was collected August 8, 2026–September 18, 2026; models change and so do their answers.
- It covers ChatGPT only. Other assistants answer differently, and we do not extrapolate across engines we have not measured.
- Order within a tier is arbitrary. Read the counts, not the position. Why we use tiers.
Cite this report
The Shortlist Report. (2026). Outsourced Controller and Bookkeeping: The Firms The Shortlist Report Finds. The Shortlist Report. https://www.shortlistreport.com/article/outsourced-controller-bookkeeping
Underlying counts: CSV · JSON. Every answer they were counted from: plain text · JSON. All reusable under CC BY 4.0 with attribution.