How we check our numbers
Every number on MoneyBackKit comes from an official source, and every tool shows when its rules were last checked. This page explains how we build and check the tools, so you can decide how much to rely on a result.
Where the rules come from
We build each tool from primary sources: IRS publications and revenue procedures for federal tax, the Social Security Administration for benefits, CMS and HealthCare.gov for medical billing rights, the CFPB and FTC for consumer protection, and each state's own statutes for deposit and tenant rules. For state income tax rates we use the Tax Foundation's yearly tables and the state laws they cite. The sources for each tool are listed below and on the tool itself.
How we test the calculators
The calculators have automated tests that check their results against examples we work out by hand from the official rules and tables. A tool only goes live after its tests pass, and the tests run again before every update of the site.
When we update
Tax years, wage bases, contribution limits and similar yearly numbers are kept in one place per site and checked when the official new figures are published, usually in the autumn for the next year. Each tool shows a "rules last checked" date. If a law changes mid-year, we update the tool and its date.
What our results are, and aren't
Results are estimates based on the rules and the inputs you give. They can't know everything about your situation (for example a second job, local city taxes or a special lease clause). Our letters are templates you can edit. Nothing here is legal, tax or financial advice, and we're not a law firm, tax preparer or adviser.
Found a mistake?
Email [email protected] with the tool, what you entered and what you expected. We check every report against the official source. When we fix something, we update the tool's "rules last checked" date.
Every tool, its last check and its sources
Plain arithmetic (no rules to check)