# Corporate tax provision: what AI models recommend, September 2026

Gane Index, September 2026 Edition. Asked as "corporate tax provision software" and as "income tax compliance software", six framings each, to twelve models with search on, on behalf of a mid-market B2B company. Page: https://www.gane.ai/index/finance/tax/corporate-tax-provision/2026-09

This is the permanent record of the September 2026 Edition, published September 17, 2026 and superseded since. The current standing: https://www.gane.ai/index/finance/tax/corporate-tax-provision/index.md

**Standing:** Thomson Reuters ONESOURCE Tax Provision leads with 36% of first choices; verdict contested. 42 first choices across the direct, paraphrase, budget and scale prompts.

## First-choice share

| Rank | Product | Share | Negative rate | Labels |
|---|---|---|---|---|
| 1 | [Thomson Reuters ONESOURCE Tax Provision](https://www.gane.ai/index/finance/vendors/thomson-reuters-onesource-tax-provision/index.md) | 36% | 15% | 52 |
| 2 | [Bloomberg Tax Provision](https://www.gane.ai/index/finance/vendors/bloomberg-tax-provision/index.md) | 10% | 14% | 43 |
| 3 | [Longview Tax](https://www.gane.ai/index/finance/vendors/longview-tax/index.md) | 7% | 18% | 28 |
| 5 | [Avalara](https://www.gane.ai/index/finance/vendors/avalara/index.md) | 7% | 27% | 11 |
| 16 | [Vertex](https://www.gane.ai/index/finance/vendors/vertex/index.md) | 2% | 40% | 10 |
| 18 | [Sovos Tax Provision](https://www.gane.ai/index/finance/vendors/sovos-tax-provision/index.md) | 0% | 0% | 21 |
| 21 | [Workiva Tax and Provision](https://www.gane.ai/index/finance/vendors/workiva-tax-and-provision/index.md) | 0% | 8% | 12 |
| 22 | [CSC Corptax Accounting for Income Taxes](https://www.gane.ai/index/finance/vendors/csc-corptax-accounting-for-income-taxes/index.md) | 0% | 33% | 24 |

Rank is by share of first choices among all 84 products named; products with the same share are tied, and the order among them carries no meaning. The table lists those with at least 10 labels.

## Each model's first choice on the direct prompt

- Claude Haiku 4.5: no first choice; alternatives Bloomberg Tax Provision, CSC Corptax Accounting for Income Taxes, Longview Tax, Thomson Reuters ONESOURCE Tax Provision
- GPT-5.4 mini: Thomson Reuters ONESOURCE Tax Provision; alternatives CCH Axcess, Longview Tax, Onesource Income Tax
- Gemini 3.5 Flash: Bloomberg Tax Provision; alternatives Exactera Tax Provision, Longview Tax, Thomson Reuters ONESOURCE Tax Provision, Vena Solutions
- Perplexity Sonar: Thomson Reuters ONESOURCE Tax Provision; alternatives CSC Corptax Accounting for Income Taxes, Wolters Kluwer CCH Tagetik Tax Provision
- Grok 4.20: Thomson Reuters ONESOURCE Tax Provision; alternatives TaxPoint, Taxfyle, Vertex Tax Accounting
- Mistral Small: Thomson Reuters ONESOURCE Tax Provision; alternatives Sovos Tax Provision, Vertex Tax Accounting
- DeepSeek V4 Flash: Bloomberg Tax Provision, Thomson Reuters ONESOURCE Tax Provision; alternatives Sovos Tax Provision, Vertex Tax Accounting
- Llama 4 Maverick: Thomson Reuters ONESOURCE Tax Provision; alternatives Avalara, CCH Axcess Tax, Taxfyle
- Qwen 3.7 Flash: Longview Tax; alternatives Bloomberg Tax Provision, CSC Corptax Accounting for Income Taxes, Thomson Reuters ONESOURCE Tax Provision
- Kimi K2: Thomson Reuters ONESOURCE Tax Provision; alternatives FloQast Tax Provision, Longview Tax, Lucasys Tax Provision, Sovos Tax Provision
- GLM 4.7 FlashX: Thomson Reuters ONESOURCE Tax Provision; alternatives Bloomberg Tax Provision, Longview Tax, Sovos Tax Provision
- MiniMax M2.5: Bloomberg Tax Provision, Thomson Reuters ONESOURCE Tax Provision; alternatives CCH Tagetik Tax Provision & Reporting, Taxfyle, Vertex Tax Accounting

## Sources the answers cite

67 of 72 answers came back with a source list, from 12 of 12 models. Sites named in the most answers:

- worldmetrics.org: 42 answers, 98 citations
- pro.bloombergtax.com: 40 answers, 75 citations
- zipdo.co: 39 answers, 56 citations
- tax.thomsonreuters.com: 38 answers, 67 citations
- gitnux.org: 37 answers, 68 citations
- wifitalents.com: 30 answers, 50 citations
- cbh.com: 21 answers, 24 citations
- capterra.com: 17 answers, 26 citations

Pages named in the most answers:

- https://zipdo.co/best/corporate-tax-provision-software (32 answers)
- https://worldmetrics.org/best/tax-provision-software (28 answers)
- https://wifitalents.com/best/tax-provision-software (24 answers)
- https://pro.bloombergtax.com/insights/tax-solutions/buyers-guide-how-to-find-the-right-tax-provision-software (23 answers)
- https://worldmetrics.org/best/corporate-tax-software (20 answers)
- https://cbh.com/insights/articles/tax-provision-automation-guide-benefits-software-roadmap (18 answers)
- https://tax.thomsonreuters.com/en/tax-accounting/tax-software-for-larger-businesses (17 answers)
- https://worldmetrics.org/best/corporate-tax-provision-software (17 answers)
- https://gitnux.org/best/tax-provisioning-software (15 answers)
- https://rightworks.com/blog/best-accounting-tax-software-applications (15 answers)

## Warned against

- Excel: 7 of 8 labels negative. "Many companies rely upon Excel for calculating their provision for income taxes, but many limitations exist when trying to use Excel to accurately calculate income taxes under ASC 740." (Claude Haiku 4.5, negative prompt)
- Thomson Reuters ONESOURCE Tax Provision: 8 of 52 labels negative. "Enterprise Options to AVOID on a Limited Budget | Thomson Reuters ONESOURCE | $200K–$2M+/year" (Kimi K2, budget prompt)
- CSC Corptax Accounting for Income Taxes: 8 of 24 labels negative. "Avoid for Limited Budgets ... Corptax (Wolters Kluwer): Average deal sizes are ~$80k\u2013$130k" (Qwen 3.7 Flash, budget prompt)
- Longview Tax: 5 of 28 labels negative. "Avoid: Longview, ONESOURCE, Workiva, Oracle Tax Reporting, and Corptax." (DeepSeek V4 Flash, budget prompt)

## Record

- Method: https://www.gane.ai/index/finance/methodology
- License: CC BY 4.0. Cite as Gane Index, September 2026 Edition, www.gane.ai/index/finance.