Please note IAS 18.19 reads as follows "Revenue and expenses that relate to the same transaction or other event are recognized simultaneously; this process is commonly referred to as the matching of revenues and expenses". Time of the payment to the seller is not relevant here. This is the matching concept in Accounting.
Refer to IFRS conceptual framework 4.49 "Expenses are recognised in the income statement when a decrease in future economic benefits related to a decrease in an asset or an increase of a liability has arisen that can be measured reliably. This means, in effect, that recognition of expenses occurs simultaneously with the recognition of an increase in liabilities or a decrease in assets (for example, the accrual of employee entitlements or the depreciation of equipment)."
Therefore you need to recognize this expenses for the period it relates.
