Pens, paper, printer ink, folders, and other supplies used in running your business are among the simplest deductions available. Office supplies purchased for business use are fully deductible as an ordinary and necessary business expense in the year you buy them. This applies to both traditional office supplies and digital supplies like software downloads used for a single project. Supplies you buy but do not use during the year may need to be treated as an asset rather than an immediate deduction in some situations, but for most small businesses this is not a practical concern. Keep your receipts and make sure the items genuinely serve a business purpose.