That does not matter. All that matters when using Billable Expenses is that the expense is billable to the customer. But it is your choice whether to use the feature or not. I can only tell you it is very handy.
OK I realize that, but still the functionality of the two forms (billable and claim expenses) remains the same (at least to me…).
Definitely not. Expense claims do not involve movement of money from company bank or cash accounts. They create liabilities or credit capital accounts and debit expense accounts. Billable expenses do involve payments from bank or cash accounts, but debit an asset account awaiting invoicing, when they are transferred to Accounts receivable. Billable expenses never show up in your company profit and loss statement. They are passed through to the customer.