Sources and method
These tools deal with money, tax and company filings, where wrong information is expensive. This page explains where our data comes from, how we label it, how often we review it, and how we make money.
Where the data comes from
Fees, taxes and deadlines come first from the agencies that set them: each state's Secretary of State or Division of Corporations, state tax agencies, the IRS and FinCEN. Only where an official page is silent do we rely on statute text or reputable secondary sources, and we say so on the page.
Every tool page lists its source URLs at the bottom so you can check each one yourself.
How we label figures
How often we review
Every tool page shows the date it was verified. We review at least quarterly, and when a rule changes (for example, Delaware's LLC tax rising from $300 to $400 in 2026) we update as soon as we can and note it under "Recent rule changes" on the home page.
How the residential address data is built
The address list comes from Anytime Mailbox's public location listings. Each address is classified with USPS Residential Delivery Indicator (RDI) data and only residential addresses are kept. Classification relies on third-party address databases and can be wrong, so every address has a "Verify" button that lets you check it again on Smarty.
Your data
The calculator and compliance calendar run in your browser. What you enter is not sent to our servers. Some inputs are saved in your browser's local storage so they are there next time; clearing your browser data removes them.
The only exception is email reminders for the compliance calendar. If you sign up, we keep your email address, state, formation date and extension choice to work out your deadlines and send the reminders. We use them for nothing else and send no marketing. Every email has a one-click unsubscribe, which deletes all of it at once; sign-ups not confirmed within 7 days are deleted automatically.
How the address checker handles data
Results come from USPS address data via Smarty, a CASS-certified provider. If Smarty is unavailable we fall back to Geocodio for the residential/commercial flag; it cannot tell CMRA status, and the result says so.
So the next person who checks the same address gets an answer faster, we keep the standardized address and its result for up to 90 days, then check again. We do not record who checked: there is no sign-up and we do not store IP addresses; free checks are counted only with irreversible hashes of a browser ID and IP. Credit codes store only the remaining balance; your payment email stays with Stripe, not in our database.
Referral links
Some outbound links are referral links (for example the Anytime Mailbox links on the address page). Using them costs you nothing extra and may earn us a small commission that pays for keeping the data current. Referral links are marked sponsored. Commissions do not affect what goes into our comparisons or how they are ordered.
Not legal or tax advice
This site helps you understand the rules and prepare. It does not replace a licensed accountant or attorney. Multi-member LLCs, LLCs taxed as corporations, and businesses with US operations or US-source income follow different rules, so get professional advice.
Found an error?
If a figure is out of date or wrong, email contact@upthos.com, ideally with a link to the official source. Once we verify it we update the page and its verified date.