Within Bill4Time you have an Accounting Isolation option which can be set either at the Settings level to default to all clients or per client.
Client Accounting Isolation: This means that all projects under your client will default to bill on one invoice and the balance due for the client will be all project totals combined.
Project Accounting Isolation: This means that all projects under your client will be completely separate with the balance due for each project only. When you create invoices they will default to be on separate invoices and when applying payments you will choose the client/project the payment belongs to.
*Please note that if you make changes either to the whole account or per client, then you will need to go back and edit each payment/adjustment you made that is not applied to any invoices to point them to the right project they belong to or the accounting will not be accurate.
To make changes to the whole account go to Settings- System tab and click Edit Settings. From there change the Accounting Isolation from Client to Project and click Save Changes.
To make changes per client, go to Clients in your blue menu bar, click on a particular client you need and click Edit Details. From there change the Accounting Isolation from Firm Default to Project and click Save.