Email hello@tindakit.com. I usually reply within two working days.
What to include
- Reporting a wrong rate: the platform, your category, the rate you see in Seller Center, and a screenshot if possible.
- Suggesting a tool: what you're trying to work out, and how you do it today.
- A calculator gave a strange result: use "Copy link to this result" on the calculator and paste the link in your email, so I can see exactly what you entered.
I can't give personal tax or legal advice. For that, please talk to a licensed accountant or the BIR.