• Information to substantiate your claims for all of your home-based business expenses. 
• How you worked out the business portion (for example, a diary over a representative four-week period or records of how you calculated the percentage of your floor plan dedicated to your business).

Tax invoices or receipts for: 

• purchase and repairs of furniture and equipment used for your business 
• utility bills and cleaning expenses 
• mortgage interest, rent, insurance and council rates (if you claim occupancy expenses) 
• rental contract between homeowner and business (if you claim occupancy expenses) 
• diary evidence of calculations