Most individuals are required to file their income tax returns on or before April 30 of the following calendar year. Interest on outstanding amounts begins to accumulate after that deadline. If you’re owed a refund, it doesn’t make any sense to wait until that date—much less past that date. File as soon as you have all your documentation.
There is one major exception to the April 30 rule. If you or your spouse or common-law partner carry on a business as a sole proprietor or in a partnership (other than as a member of a limited partnership) during the year, you both have until June 15 of the following year to file your returns. However, any taxes owed by you and your spouse or common-law partner must be paid by the April 30 date to avoid interest charges.
Tax tip: Anticipating a refund on your 2013 tax return? Then you should still file your return as early as possible. Interest on refunds will only be paid starting from whichever of the following three dates is latest: May 31, 2014; the 31st day after you file your return; or the day after you overpaid your taxes.