A financial institution that has been designated as an authorized federal tax depository, and acts as a fiduciary for at least 200 taxable trusts that are required to pay estimated tax, is required to deposit the estimated tax payments electronically using the Electronic Federal Tax Payment System (EFTPS).
A fiduciary that is not required to make electronic deposits of estimated tax on behalf of a trust or an estate may voluntarily participate in EFTPS. To enroll in or get more information about EFTPS, visit the EFTPS website at www.eftps.gov or call 1-800-555-4477. Also, see Pub. 966, Electronic Federal Tax Payment System: A Guide to Getting Started.