Integration in smallinvoice from Lourens Systems


Login to your smallinvoice account via



  1. Click Home
  2. Click Configuration
  3. Click Integration
  4. Click on the payrexx logo to configure the settings: 


  1. Click Edit 
  2. Enter your Payrexx Account name such as
  3. Insert the API Secret that you copied from the Payrexx backend (see next screenshot
  4. Click the link and choose the PSP's and payment methods 
  5. Enter the ID's of the PSP's and payment methods that you want to appear (you'll find the PSP ID's here:


  1. Click Settings
  2. Click API 
  3. Enter the URL
  4. Choose Normal (PHP-Post) 
  5. Click Save and wait
  6. Double click on the API Secret in order it gets blue and click the right mouse button
  7. Click "Kopieren" respectively "Copy


Create a new invoice: 


  1. Click on PAYMENT 
  2. Make sure that PAYREXX is set to "Generate and print


Now the payrexx payment link appears on the invoice: 


Did you find it helpful? Yes No

Send feedback
Sorry we couldn't be helpful. Help us improve this article with your feedback.