Importing Vendor and Customer History

A client wants to bring 12 months Customer and Vendor history from their old system into Attain. Open and closed entries. I think the best approach is to bring all entries in as open via a general journal then to ‘apply’ them to each other as a batch process. I have application history from their old system, so this is possible. I realise I will have to bring in some entries which are older than 12 months, where these were closed by entries from the last 12 months. My confusion is how to deal with invoices that were closed by two part-payments or which are open and part-paid. One question is how to set the value that is being applied, where this is less than the ‘Remaining Amount’. I have looked at the application code, but cant quite get it. Can some please enlighten me ?

You need to decide which information is the more important - billing or paying. For most clients it is billing. So my normal approach is to simply take each invoice, and apply all the payments made to it as one check on the date of the last payment. This is a lot less work, and converts generally much easier.

Thanks for the advice. Am I right to think that it is impossible to post an application so that a payment part-pays specific invoices ?