How do I bill for travel time?

Travel time will fall into the expense category.

If your project is on-site, your daily travel expense to the client’s office is NOT reimbursed.
If a client has you travel to a conference, then your travel expenses will most likely be covered. That said, you must get client approval before you travel.

For more information on expenses, see What expenses should I be reimbursed for? and How to record your expenses.