The Internal Revenue Service has unveiled improvements in its Electronic Federal Tax Payment System at www.eftps.gov.

Taxpayers may now schedule all four estimated tax payments on Form 1040ES at one time; access their payment history for the past 16 months; and search, print or download payment history by date, tax type, amount, tax form and other factors.

The upgraded site enables users to change bank accounts by phone without completing a new enrollment and to select a new personal identification number online when changing a bank account number

The site provides links to states with electronic tax payment systems.

IRS introduced online payment in 1996. More than 4 million taxpayers have enrolled in the system to make their payments electronically.

Taxpayers can make payments 24 hours a day, 7 days a week. Businesses may schedule payments up to 120 days in advance (365 days in advance for individuals). For easy record keeping, taxpayers receive an EFT Acknowledgement Number for every transaction.

You can enroll by visiting the website or by calling EFTPS Customer Service at 1-800-555-4477.