Withholding Toolbox
Payroll Taxes
To provide guidance in completing the W4 form, employees can visit the IRS Withholding Estimator or view this video to review the W4 steps.
For state tax withholding, many states previously allowed employees to use the Federal W-4 to instruct an employer to withhold state taxes. Recent changes to the Federal withholding form have prompted some states to change tax filing rules state for withholding.
Year End Tax Forms
Caltech's Payroll Services office issues W-2 forms no later than January 31, following the close of the tax year. The W2 may not be the only form you need to complete your tax filing. Below is a list of common tax forms issued by the Institute. Please use this list to contact the correct department for various tax forms. The hyperlink under "Issuing Department" will take you to that web page.
| Form | Form required to be mailed by: | Available Electronically? | Issuing Department* | Contact Number |
|---|---|---|---|---|
| W-2 | January 31, 2025 | With Credentials | Payroll Services | 626-395-8668 |
| 1042-S | March 17, 2025 | Yes | Payroll Services | 626-395-8668 |
| Fellowship Letter | January 31, 2025 | No | Payroll Services | 626-395-8668 |
| 1098-T | January 31, 2025 | With Credentials | Bursar | 626-395-2988 |
| 1095-C | March 3, 2025 | No | Benefits | 626-395-6443 |
| 1099-MISC | February 17, 2025 | No | Payment Services | 626-395-3689 |
| 592-B | January 31, 2025 | No | Payment Services | 626-395-3689 |
IRS W4 Frequently Asked Questions W-4 Video: How to Complete the W-4
Submitting Tax Changes To Payroll
Payroll Services Dropbox (Secure website for document upload)