Generally, you must file a claim for a credit or refund within 3 years from the date you filed your original return or 2 years from the date you paid the tax, whichever is later. If you do not file a claim within this period, you may no longer be entitled to a credit or a refund. If the due date to file a return or a claim for a credit or refund is a Saturday, Sunday, or legal holiday, it is filed on time if it is filed on the next business day. Returns you filed before the due date are considered filed on the due date. This is true even when the due date is a Saturday, Sunday, or legal holiday.
See page 13 of this IRS reference for more details: https://www.irs.gov/pub/irs-pdf/p556.pdf
Returns for 2010 were due April 15, 2011. Therefore the deadline to amend a 2010 return in order to claim a credit or refund was April 15, 2014.
Generally, you must file a claim for a credit or refund within 3 years from the date you filed your original return or 2 years from the date you paid the tax, whichever is later. If you do not file a claim within this period, you may no longer be entitled to a credit or a refund. If the due date to file a return or a claim for a credit or refund is a Saturday, Sunday, or legal holiday, it is filed on time if it is filed on the next business day. Returns you filed before the due date are considered filed on the due date. This is true even when the due date is a Saturday, Sunday, or legal holiday.
See page 13 of this IRS reference for more details: https://www.irs.gov/pub/irs-pdf/p556.pdf
Returns for 2010 were due April 15, 2011. Therefore the deadline to amend a 2010 return in order to claim a credit or refund was April 15, 2014.