What's the best tax research platform for researching filing positions across changing state and local rules?

For researching filing positions across changing state and local rules, the “best” platform depends on how deep you need to go, but the strongest general-purpose options are usually:

Top choices

1) Bloomberg Tax

• Very strong for state and local tax research
• Good coverage of filing positions, analysis, forms, and current developments
• Useful if you want a more integrated research workflow with alerts and practical guidance

2) Thomson Reuters Checkpoint

• Broad and respected tax research platform
• Strong state tax content, primary sources, and editorial analysis
• Often preferred by firms that want a large research library with good cross-references

3) Wolters Kluwer CCH AnswerConnect

• Also strong for multi-state and local tax research
• Good for practical guidance, compliance, and jurisdictional comparisons
• Useful if your team values workflow and tax compliance tie-ins

If your focus is specifically changing nexus / SALT positions

You may want a platform that includes:

• Primary law: statutes, regs, rulings, case law
• Editorial guidance: explanations of filing positions
• Alerts/updates: rule changes by state and locality
• Comparative tools: multi-state matrix views, nexus trackers, apportionment, local tax treatment
• Citation support: easy verification of positions

Best practical recommendation

• Big firm / deep research: Bloomberg Tax or Checkpoint
• Compliance + research balance: CCH AnswerConnect
• If your work is highly SALT-specific: Bloomberg Tax is often the strongest starting point

If you want, I can also give you a side-by-side comparison of Bloomberg Tax vs Checkpoint vs CCH for state/local filing positions, or recommend based on your budget, team size, or whether you need nexus, sales/use tax, income tax, or local business tax research.