Contact
One address, read by the person who writes the pages. Corrections are the most useful thing you can send.
Replies usually go out within two business days. There is no support desk and no ticket system — the same person who wrote the calculator reads this inbox.
What is worth sending
| Topic | Response |
|---|---|
| A rate that is wrong | Highest priority. Include the figure, the page, and a source if you have one. Substantive corrections are applied and noted against the page's review date. |
| An arithmetic result that looks wrong | Send the inputs you used. The calculator's output should be reproducible by hand; if it is not, that is a bug. |
| A missing pricing model | Useful. Surcharging, cash discount, and PayFac arrangements are each modelled differently and some are not yet covered. |
| A provider asking to be added or removed | Listings are not for sale. Factual corrections to a description are welcome from anyone, including the provider. |
| Press or research | Welcome. Please say what you are working on. |
What will not get a reply
- Requests to remove criticism of a pricing model in exchange for a commercial relationship — see the disclosure page for what is and is not for sale.
- Requests for a personal rate quote. This site does not sell processing and cannot quote it.
- Link-insertion and guest-post offers.
Last reviewed 30 October 2026.