One person runs this site. There is no support desk, but messages do get read.
The fastest way
@phillips9320 on X. Open messages, usually answered within a day or two.
What to get in touch about
- A wrong figure. Please — see corrections. This is the one I most want to hear about.
- A calculator you wish existed. Genuinely useful; a lot of what gets built next comes from these.
- Something broken on a page, or a result that looks impossible.
- Press or licensing. The underlying tax dataset is maintained carefully and can be discussed.
What I cannot help with
I cannot tell you what to put on your W-4, work out your personal tax position, or advise on a financial decision. I am not a CPA or a tax attorney, and doing that would be both unhelpful and a bad idea. For anything specific to your circumstances, talk to your payroll department or a professional.