Terms of use
Terms of use
Plain-language terms for using Line 4C.com. By using this site you agree to them.
1. What this site is
Line 4C.com (the “site”) is a free, informational calculator and explainer about Form W-4 Line 4(c) “Extra withholding” for people who work two jobs (or dual-income couples filing jointly). It is operated by Red Goggles LLC (“we,” “us”). By accessing or using the site you agree to these terms; if you don’t agree, please don’t use the site.
2. Not professional advice
The site provides general information and estimates for educational purposes only. It is not tax, legal, financial, or accounting advice, and using it does not create any professional or advisory relationship. Estimates are not guarantees of any withholding, refund, or balance-due outcome. Always confirm your specific situation on the current-year Form W-4 and its Multiple Jobs Worksheet, with the IRS Tax Withholding Estimator, or with a qualified tax professional. See our full disclaimer.
3. Accuracy and “as is”
We build the calculator from the published IRS Form W-4 Multiple Jobs Worksheet and take accuracy seriously, but the underlying tables, dollar thresholds, and pay-period conventions change annually and can contain errors. The site is provided “as is” and “as available,” without warranties of any kind, express or implied, including accuracy, completeness, fitness for a particular purpose, or non-infringement. We don’t warrant that the site will be uninterrupted or error-free.
4. Limitation of liability
To the fullest extent permitted by law, Red Goggles LLC will not be liable for any indirect, incidental, consequential, or special damages, or for any decision you make based on the site or its estimates — including how much you enter on a W-4. Your sole remedy if you’re dissatisfied is to stop using the site.
5. Your inputs and privacy
The calculator runs entirely in your browser; we don’t collect the salaries, filing status, or pay-frequency values you enter. Your use of the site is also governed by our privacy statement.
6. Intellectual property
The site’s text, design, and code are owned by Red Goggles LLC or used under license. You may read, share links to, and quote reasonable excerpts with attribution. You may not copy the site wholesale, or scrape or republish it as your own.
7. Third-party links and advertising
The site links to third-party resources (such as IRS pages and sibling calculators) and is supported by display advertising. We don’t control third-party sites or ads and aren’t responsible for their content, accuracy, or practices.
8. Changes
We may update the site and these terms from time to time. Continued use after a change means you accept the updated terms.
9. Contact
Questions about these terms? Email [email protected] or use our contact page.
Last updated: June 4, 2026