The ATO has given some guidance on how they will review phone and internet. If your claims are less than $50 for these expenses, the ATO will feel these are incidental amounts and will not require substantiation. Amounts over will need evidence of the claim.

• Keep records for a 4-week representative period each year
• From itemised bills you need to determine the percentage of work use by –
  • Number of work calls as a percentage of total calls
  • Amount of time spent on work calls as a percentage of total
  • Amount of data downloaded for work as a percentage
• Evidence that employer expects work to be done at home or make some work calls will also help demonstrate deduction is claimable.