Studio Ninja is primarily a client and project management software.
We help you create and manage your invoices (income) but not your expenses. We prefer to let dedicated accounting software like Xero, Rounded or Quickbooks for example manage your expenses as part of their bookkeeping features.
If you have an accountant, we recommend that when you set up your Studio Ninja account, invite your accountant as an additional user under Settings > Company Users. This way your accountant will have easy access to all your invoices generated in Studio Ninja.
Alternatively, you can export all your payments to a CSV file and send that to your accountant during tax time.