You can customize your invoices in Xpert-Timer and enter any prices to be charged. These can either be made up of different services, or you can simply charge your customer a flat rate.
In the first step, choose whether you want to calculate the sales tax in your invoice from the individual items or from the total net amount. You can find the settings for this in Configuration -> System -> Invoice.
There are various invoicing options available to you:
1.Right-click on the customer to be billed in the project manager and select "Write invoice." Here you will see a list of all the customer's services and timestamps for all their projects that have not yet been billed.
2.Bill for a specific project by right-clicking on the project.
3.Record multiple services during the project and bill for them via service management, e.g., at the end of the month. Go to the "Window" menu and select "Services/Costs" to open the "Service Management" dialog box. Here, you can select the relevant service items for billing.
It is also possible to generate an invoice from a quote. More information can be found here.