Prepay Expenses Under the IRS Safe Harbor If you’re on the cash basis, you can prepay qualifying expenses up to 12 months in advance and deduct them this year. That includes office rent, equipment leases, and insurance premiums. For example, if your monthly office rent is $3,000, prepaying $36,000 on December 31st to cover your 2026 rent gives you a $36,000 deduction in 2025 and provides the landlord with income when he wants it, in 2026. Be sure to mail the funds on December