firmly is a version of the fillup application dedicated to small businesses. Ultimately, it will enable you to run a small business on your own. Its functionalities include issuing and sending invoices integrated with the National e-Invoice System (after the introduction of the KSeF obligation), integration with Autopay fast payments so that you can quickly receive money from contractors, sending JPK_V7K, JPK_V7M and generating the JPK_FA file. Net Invoice is available for free, but using other invoice creators requires purchasing a Firmly subscription.