Contact BizCalcTool
If a marketplace fee changed, a tax bracket moved, or a calculator is missing something you need, tell us — rate changes are the most common reason a model drifts.
Write to [email protected] with the tool name and your inputs. For fee disputes include the marketplace, category and size tier.
What we fix fastest
- Published rate or bracket changes, with a link to the source
- Arithmetic errors — include expected versus actual output
- Missing formats: Etsy offsite ads, Amazon oversize tiers, multi-state payroll
What we will not do
We do not give tax, legal or investment advice and cannot review your personal return. For filing questions, work with a CPA.
Reporting a calculation error
Include the tool, your exact inputs and the number you expected. If it is a fee or bracket change, link the source page — marketplace rate cards and IRS publications are the fastest way to get a fix verified and shipped.
Embedding and linking
You may link to any calculator or quote a result with attribution. Please do not iframe the whole site or republish the tools as your own; if you want a custom integration for a course or community, email us and we will talk about it.
Response time
Usually a few business days.
Frequently Asked Questions
Can you add my country's tax rules?
Tell us which country and which tax; we prioritise the US, UK, CA and AU.
Do you offer API access?
No — the tools are browser-only by design.