TIN ComplianceA resource from TIN Comply
Calculators

TIN compliance calculators and downloads

Seven calculators that run in your browser (nothing you enter is sent anywhere), plus the letter templates, the solicitation log and the compliance calendar.

Calculator

B-Notice deadline calculator

Enter the CP2100 date and get the send-by, payee-response and backup-withholding dates in business days, federal holidays excluded.

Calculator

972CG penalty estimator

Estimate an IRC 6721 penalty by tier and year, with the annual maximums and the matching 6722 payee-statement penalty.

Calculator

TIN format checker

Check whether an SSN, ITIN or EIN is even a valid format before you send it to the IRS. Runs in your browser; nothing is stored.

Calculator

Solicitation deadline calculator

Enter the account-open date and get the first-annual and second-annual W-9 solicitation deadlines that keep a missing-TIN penalty waivable.

Calculator

Backup withholding calculator

Payment in, 24% withheld and net out, with the Form 945 line and 1099 box each figure goes to.

Calculator

Do I need to send a 1099?

Four questions, the federal answer: which form and box, the threshold for the year, and the corporate, card-payment and foreign-payee exceptions.

Calculator

Vendor file health check

Drop in a CSV of names and TINs and get the structural problems before the IRS finds them. Runs entirely in your browser.

Templates

B-Notice letters & reasonable-cause statement

Word templates based on the samples in Pub 1281, ready for your letterhead.

Calendar

Compliance calendar 2026–2027

Every filing, 945, solicitation and notice-season date; add your own CP2100 date and download or subscribe.