Free tools for vendors
BookNox publishes six free tools for the money side of independent service work: an invoice generator, two tax calculators, two fee calculators, and a signature generator. Every one is free, needs no account, and lives at booknox.com/tools with nothing to install and no email gate.
Available tools
The current tools:
- Invoice generator, a clean PDF invoice to download: booknox.com/tools/invoice-generator
- SE tax calculator, self employment, federal, and state tax with the QBI deduction, with a page for every state and Washington, D.C.: booknox.com/tools/self-employment-tax-calculator
- Quarterly tax calculator, the IRS safe harbor math behind your four estimated payments: booknox.com/tools/quarterly-estimated-tax-calculator
- Stripe fee calculator, what a charge actually nets after processing: booknox.com/tools/stripe-fee-calculator
- Fee calculator, what a percentage booking platform fee costs over a full year: booknox.com/tools/fee-calculator
- Signature generator, a drawn or typed signature downloaded as a clean image: booknox.com/tools/signature-generator
How do the two tax calculators work together?
Start with the SE tax calculator. Enter your net business income and it estimates self employment tax, federal income tax, and your state's income tax, then shows a quarterly payment to plan around. Each state page is built on that state's 2026 tax rules.
The quarterly tax calculator picks up from there. It applies the federal safe harbor rule in 26 U.S.C. 6654: paying 100% of last year's tax, or 110% if last year's adjusted gross income was over $150,000 ($75,000 if married filing separately), generally avoids the underpayment penalty however your income swings during the year. Both calculators give estimates for planning, not tax advice.
Sources, read October 22, 2026: 26 U.S.C. 6654: the 100 and 110 percent safe harbors and the $150,000 threshold.
How the SE tax calculator estimates
The SE tax calculator follows the federal method in a simplified form. It applies the self employment tax rate the IRS publishes, 15.3% (Social Security plus Medicare), to your net earnings, then estimates federal income tax after the standard deduction and a simple 20% qualified business income deduction, and adds your state's tax. It does not know about your other income, credits, or retirement contributions, so treat the result as a planning number to check with your tax preparer.
Sources, read October 22, 2026: IRS: the 15.3% self employment tax rate; IRS: the qualified business income deduction of up to 20 percent.
The fee calculators
The Stripe fee calculator works in both directions for card, ACH, Apple Pay, and Google Pay payments: forward (what lands from a $1,000 charge) and reverse (what to charge so $1,000 lands). As of October 22, 2026, Stripe's pricing page lists domestic cards at 2.9% plus 30 cents per successful transaction and ACH Direct Debit at 0.8% with a $5.00 cap.
The fee calculator answers a different question: what a booking platform that takes a percentage of every booking costs you over a year. Enter your yearly booking revenue and the platform's percentage, and it compares that cut with BookNox's flat $348 a year (12 months at $29, before sales tax). At the default $60,000 in bookings and an 8% fee, the cut is $4,800 a year. Card processing is left out of that comparison on purpose, because it applies on any platform.
Sources, read October 22, 2026: Stripe pricing: card and ACH Direct Debit rates.
The invoice and signature tools
The invoice generator turns a short form into a real PDF invoice you can download and send, with no account and no watermark. The PDF is generated from what you type and sent straight back to your browser; nothing you enter is stored.
The signature generator turns a drawn or typed signature into a PNG with a transparent background, sized for documents, email footers, and PDF fields. The image is made in your own browser and downloaded from there, so it never reaches BookNox. For client contracts, BookNox proposals carry the signature step inside the booking flow instead.
Who the tools are for
The tools are built for independent service businesses: photographers, DJs, planners, coaches, tutors, and anyone else who invoices clients and pays quarterly estimated tax. None of them needs a BookNox account, and using them never signs you up for anything.
Is a signature image a legal signature?
The federal ESIGN Act says a signature may not be denied legal effect solely because it is in electronic form, but a pasted image carries no record of who placed it or when. BookNox proposals capture the signer's consent, the timestamps, and an audit trail, which a pasted image cannot. For anything important, check with your own attorney.
Sources, read October 22, 2026: 15 U.S.C. 7001 (ESIGN): no denial of legal effect solely for electronic form.
Sales tax on invoices
The invoice generator has a tax rate field that adds a tax line to the total, and its guide suggests showing a deposit already paid as a credit so the balance due is clear. Whether sales tax applies to your service, and at what rate, is for you to confirm with your state or an accountant.
Do the tools save anything about me?
No. None of the tools asks for an email or an account. The calculators run in your browser, the signature image never leaves it, and the invoice generator keeps no copy of your invoice. Close the tab and nothing remains with BookNox.
Why the tools are free
The tools run the same kind of math BookNox uses inside the product, and they are useful on their own. A vendor who outgrows one off invoices usually needs the full flow: quote, contract, deposit, and calendar in one link. That is the paid product, a flat $29 a month plus applicable sales tax with no booking fee taken. The tools stay free either way.