The Internal Revenue Service website offers information about the deadlines to contribute to a simplified employee pension individual retirement account. Financial institutions that offer SEP IRA accounts to customers may also have contribution information listed on their website, states Charles Schwab.
Individuals can contribute to their SEP IRA before the deadline for filing income taxes for that year. If an individual files for an extension, that also extends the contribution deadline, states the IRS. As of 2015, the deadline to file taxes for a given year is on April 15th of the following year, advises USA.gov.
Individuals are not required to invest in the plan each year, states the IRS. Contribution limits are adjusted each year. As of 2015, individuals can contribute up to $53,000 per year or 25 percent of their total income, whichever is less.