IMHO: $1,785 is not a material amount. If possible, you could track it down in client's books and correct the date of the transaction(s) to 2014 before finishing the 2014 tax return (preferred). We can assume the 2013 tax return is correct, and the client's 2014 books are wrong due to his violation of the closing period. Or simply report the amount as 2014 income and finish the tax return now rather than amend the 2013, and then spend the necessary time to find the badly dated transaction(s) in client's books and fix them later. This would not be my advice if the amount was material. I wouldn't change the balance sheet or the M-2 or create a prior period adjustment as these options will result in an understatement of income. This is a timing issue and a relatively small amount, but I would still recognize it as income either in 2013 by amending the return or else in 2014 by adding it to gross revenues.