If you requested to have the House Account payment option enabled at your POS, you will then see a new HOUSE ACCT button on your payment screen. 

When clicking on this button, it will apply a "House Acct" payment to the ticket and generate an invoice in PeopleVine for your customer. 

You can see this order marked as "Due" with an "Invoiced" flag, meaning that we are pending payment on this invoice before we can mark it as paid in full.  

When enabled (under company settings), your customer will automatically be charged on the 1st of the month for any open invoices they currently have.  You can also go to Sell > Transactions > View Open Invoices to see open invoices and take payment one at a time.