As Plan Administrator of your 401k, you are responsible for tracking the funds of your 401k. The monies in your 401k should be kept accounted for separately.
Types of monies include:
- Employee salary deferral contribution(s)
- Employer profit sharing contribution(s)
- Roth contributions
You will need to establish a clear accounting method to keep track of each type. Accounting will include the incoming amount(s) as well as the transactions and investments for each. The format for tracking and accounting is up to you. You can use any type of accounting software, such as:
- Excel spreadsheet
- Mint (online software)