The client is running a proprietary ERP that currently integrates into QB via a web connector. It is giving off error messages and needs to resolve those so the syncs work without intervention. After this, they need to design additional data flows from the ERP to QB to enhance the data flow.
We have recently integrated Quickbooks sync into a recreational club management product. Also integrated QB desktop into the product to sync payments and credit memos with QB.
In one of the healthcare projects, we used Quickbook API to process transactions when supplied as XML to Quickbooks VM, having web services. These web services check for text files in a mapped directory with customer updates and add info and push the data into QB.
We would need some information about your ERP to analyze the error messages and resolve the issue to streamline the flow from ERP to Quickbooks.
We have also worked on 4-5 projects of QuickBooks Web connector. We provided details in the cover letter.