This is not possible. An account is one or the other. Read this Guide: https://www.manager.io/guides/8965. That said, adjustments are sometimes made to both types, For example, a sale to a customer is recorded in a sales income account. A refund subtracts from the same account.
But work done for a customer does not reduce the income account. The cost of doing work must be recorded in expense accounts, such as through payslips to workers.
The exact design of you chart of accounts is going to depend on your business organization and the nature of your operations. To track things to individual customers, you might explore using tracking codes.