Open data
Data you can take and use
The tables behind our calculators, published as files rather than locked inside a web page. Free to reuse — including commercially — as long as you credit the source.
US United States data only
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US LLC formation and annual fees by state
Filing fee, recurring fee, payment frequency and entity-level tax for an LLC in all 50 states plus DC.
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US state individual income tax 2026 (single filers)
Rate structure, brackets, standard deduction and personal exemption for all 50 states plus DC, with a worked effective rate.
Why we publish these
Both of these started as internal tables for a calculator. We publish them because building them turned up how much of the freely available data on these topics is wrong — Delaware's LLC tax republished as $400 when it is $300, and entity-level taxes missing from almost every fee table in existence. Correcting that only helps if the corrected version is somewhere people can actually take it from.
Licence
Everything here is CC BY 4.0. Free to use, republish, remix and sell, including commercially, as long as you credit the source.
Attribution can be as simple as:
Data from The Number Desk, CC BY 4.0
Stability
The file URLs are permanent. When figures change, the file changes and the dataset's page records the change with a date — we do not move or version the URL, so a link you publish keeps working and keeps pointing at current data. Each dataset page lists what changed and when.
Every response sends Access-Control-Allow-Origin: *, so you can fetch
these directly from a browser application without a proxy.
Corrections
If you find an error, tell us — it is the fastest way to get it fixed, and corrections are logged publicly on the dataset's page rather than quietly patched.