Which outsourced firms handle business tax and compliance?
Business Tax and Compliance: The Firms The Shortlist Report Finds
10 firms lead, appearing in 14.5–25.5% of 55 AI responses. The sample cannot separate them, so we do not pretend it can.
No clear leader
No single firm dominates this question. Ten come up regularly and they specialise in different things, so the firm worth calling is the one that fits your situation rather than whoever sits highest.
PwC14 of 55
Provides finance transformation, accounting operations, vendor financial due diligence, and CFO services for mid-market enterprises and private-equity-backed businesses.
BDO11 of 55
Provides bookkeeping, accounting, reporting, FP&A, and finance transformation for mid-market companies.
Deloitte11 of 55
Offers full finance-function outsourcing, automation, controllership, and transformation for mid-market and enterprise clients.
EY11 of 55
Provides finance transformation, accounting operations, and full-cycle consolidation with multi-GAAP reporting for larger companies and complex structures.
Grant Thornton11 of 55
Provides outsourced accounting, advisory, tax, and finance transformation services for mid-market and larger companies.
+5 more, tiedin the table
Based on 55 ChatGPT responses to this question, collected August 11, 2026–August 19, 2026. Firms are counted once per response. How we measure.
The ranking
| Firm | Responses | Share | |
|---|---|---|---|
| Tier 1 10 firms, 14.5–25.5% | |||
| PwCProvides finance transformation, accounting operations, vendor financial due diligence, and CFO services for mid-market enterprises and private-equity-backed businesses. | 14 of 55 | 25.5% | |
| BDOProvides bookkeeping, accounting, reporting, FP&A, and finance transformation for mid-market companies. | 11 of 55 | 20.0% | |
| Deloittedeloitte.comOffers full finance-function outsourcing, automation, controllership, and transformation for mid-market and enterprise clients. | 11 of 55 | 20.0% | |
| EYProvides finance transformation, accounting operations, and full-cycle consolidation with multi-GAAP reporting for larger companies and complex structures. | 11 of 55 | 20.0% | |
| Grant Thorntongrantthornton.luProvides outsourced accounting, advisory, tax, and finance transformation services for mid-market and larger companies. | 11 of 55 | 20.0% | |
| KPMGkpmg.comProvides full finance managed services, M&A advisory, financial diligence, and transaction support for mid-market and enterprise clients. | 11 of 55 | 20.0% | |
| RSMProvides accounting, FP&A, controllership, and CFO services to growing middle-market businesses and PE-backed companies. | 11 of 55 | 20.0% | |
| TaxJartaxjar.com | 10 of 55 | 18.2% | |
| Fondofondo.comProvides bookkeeping, tax, payroll, R&D credits, and fractional CFO services to VC-backed startups and SMBs. | 9 of 55 | 16.4% | |
| Insight R+DSpecializes in R&D tax credits and partners with CPA firms to conduct financial reviews, documentation, and filing support. | 8 of 55 | 14.5% | |
Key findings
- No firm answers “Which outsourced firms handle business tax and compliance?” reliably in ChatGPT. The most-named, PwC, appeared in 14 of 55 responses (25.5%) collected August 11, 2026–August 19, 2026, and 9 other firms scored close enough that the sample cannot put any of them in order.
- PwC, BDO and Deloitte were named most often, in 11–14 of 55 responses. All 10 firms in the leading group are listed with their counts in the table below.
- 10 firms cleared the reporting threshold on “Which outsourced firms handle business tax and compliance?” in ChatGPT as of August 19, 2026; the full table with response counts is below.
- Deloitte appears in 6 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 PwC, BDO, Deloitte, EY, Grant Thornton, KPMG, RSM, TaxJar, Fondo and Insight R+D, named in 8 to 14 of the 55 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.
The test is McNemar’s at 95%, applied against the same 55 responses for every firm. The full reasoning, and what happened when we ranked one-to-N instead.
What the sample shows
10 firms lead this question: PwC, BDO, Deloitte, EY, Grant Thornton, KPMG, RSM, TaxJar, Fondo and Insight R+D. They appear in 14.5–25.5% of the 55 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.
183 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 11, 2026–August 19, 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). Business Tax and Compliance: The Firms The Shortlist Report Finds. The Shortlist Report. https://www.shortlistreport.com/article/outsourced-tax-and-compliance
Underlying counts: CSV · JSON. Every answer they were counted from: plain text · JSON. All reusable under CC BY 4.0 with attribution.