Yes. Voiding an invoice has a direct impact on your accounting because it is the same as deleting except that CORE keeps a record of it. Just as creating an invoice debits the A/R account and credits income accounts, voiding an invoice does the reverse. Moreover, if you void an invoice for a previous reconciliation period, you need to make up for the difference using general journal entries. Check this article for details about voiding invoices, checks, and payments in a closed accounting period.