The Internal Revenue Service is putting out the word on how to beat the rush right after Presidents Day —one of the agency’s busiest weeks of the year.

The day following Presidents Day is typically the busiest day of the year for IRS telephone assistors, and the agency has extended call center hours over the long weekend.

The IRS will also soon face an extra onslaught from Earned Income Tax Credit and Additional Child Tax Credit returns stacked up due to this season’s delay in issuing refunds on returns that claim the credits. Those refunds will likely not start arriving in bank accounts or on debit cards until the week of Feb. 27—if there are no processing issues with the return and the taxpayer chose direct deposit.

IRS telephone assistors typically field thousands of calls hourly on the day following Presidents Day, which this year is February 21. Taxpayers and tax professionals calling the IRS about their account issues should be prepared to validate the taxpayers’ IDs with both the prior-year and most recently filed tax returns available.

The agency is also urging taxpayers to use online resources to ease the week’s crunch this week, such as the “Where’s My Refund?” tool. Additionally:

• If taxpayers changed their tax prep software this year, they may be asked for their adjusted gross income to help verify their IDs. Phone assistors cannot provide taxpayers with their AGI.

• If taxpayers receive an IRS Letter 4883C, it’s because the IRS stopped a questionable return. Before calling, taxpayers again must be prepared to validate their ID.

• Taxpayers who have an expired ITIN and need to file a return should be aware of new rules. ITINs issued before 2013 begin expiring this year.

• All IRS Taxpayer Assistance Centers now require an appointment for most services. Most questions can be answered at IRS.gov.

• The IRS website has a search tool to track down a topic and get the answer to a question, as well as an Interactive Tax Assistant similar to the tool used by IRS customer service representatives.

Jeff Stimpson is a veteran freelance journalist who previously served as editor of The Practical Accountant.