Yes. When you add or edit a client, the billing address is set to match the main address by default.
In the client form you will see a checkbox labeled Billing address same as address. This checkbox is checked by default, which means the billing address will automatically be the same as the main address you entered.
If you need a different billing address, simply uncheck that checkbox and a separate billing address field will appear where you can type in a different address.
If you have already set a separate billing address and want to go back to using the same address, just check the Billing address same as address checkbox again and the separate billing address will be cleared.
On the Mobile App
On the mobile app, the client form has a single Address field. The address you enter is used as both the main address and the billing address. If you need to set a separate billing address, use the web app.