Spreadsheet input control
A Sarbanes Oxley spreadsheet can only be as good as its inputs. Garbage in results in garbage out. As a result there should be strict controls over the inputs of a spreadsheet. Strict control should be maintained over who can enter inputs and controls implemented to avoid errors. These should include:
- Always backup electronic inputs received
- Have a control total to balance back to
- Build in checks within the spreadsheet that compare to the control total to identify ‘lost’ information.
- Use the Data Validation tool in Excel to stop errors creeping into spreadsheets.
How to implement input controls
Suggested input control procedures for spreadsheet files
For manual inputs the following should be in place:
- A password should control who can make changes and who can only view the file (see access controls)
- Individual cells should be protected so that only cells designated for input can be changed (watch the protection video clip by clicking on it).
- Input cells should stop unrealistic inputs e.g. if the maximum discount is 20% then a number higher than this should not be allowed. The Data Validation tool in Excel will help with this. Learn how to use Data Validation here.
For automatic inputs (copy/ pastes or direct links to other spreadsheets and databases
- A control total should be established e.g. the total US$ value of all the transaction to be downloaded is say $1 536.23. Build a control into the spreadsheet to check that the spreadsheet uses the correct input in its processing.