Your business year end determines when you can claim the expense. The fiscal year end is usually December 31, therefore you cannot claim the expenses in 2017. However, you can do one of two things; first go back and adjust your 2016 income tax. The adjustment might create a loss which can be carried forward to 2017. Secondly, you can choose a year end that ends after December. However, CRA prefers a fiscal year that ends in December 31. It is more easier to manage going with a calendar year January to December.