Sample Code to Synchronize Invoices with Accounting Software

Quantify was designed to interface with any software package, accounting software being the most common. For accounting software that doesn’t have an API (surprisingly there’s a lot out there, but we’ll save that topic for a separate post) the simplest way to do this is to export the invoices to a file, then have your end-users import the file. Although this works perfectly fine it’s still error prone as it requires end-users to remember to export, as well as other issues.

A better solution is to programmatically ‘sync’ the invoices to the accounting software. In this scenario a process is started, either by double clicking on the resultant exe or a service can be run automatically every night. The developer simply needs to make the Quantify API talk with the accounting software API.

The PDF below shows the process that Quantify uses with the built-in accounting packages, such as QuickBooks.

Invoice Sync Process Quantify.pdf (88.9 KB)

C# sample code for the Quantify side of things is below. There’s a few things to note:

  • Please log in and ask any questions here on this post.
  • First, it is highly recommended that you attend one of our billing training classes before getting serious about modifying this code. Quantify has a lot of features and you’ll be well prepared knowing how things work in the UI. To see the basic Quantify training videos please visit Quantify Help Videos - Avontus Docs Home ( For full training videos that were recorded for your company during the Quantify implementation please contact
  • This solution uses Visual Studio 2022.
  • You must have had Quantify installed on your local machine and have connected to SQL Server. This sets up the QuantifySettings.xml file (see source code in zip below for an explanation).
  • There are a lot of “TODO” comments in this code. These items are specific to your accounting software and is where you add your code. An example is fetching a customer by ID, or linking a customer that hasn’t been fetched yet. (75.8 KB)