Thinking purely about what's easier and more accurate for your lab, consider this:
1. Small accounts programs are not designed for thousands of transactions per month. Larger packages cost more, add complexity and require training.
2. LabManager is an optimised front-end Sales Order processing system, with built in Sales Ledger, designed to handle large transaction throughput. All transactions are stored without significant performance loss even with millions of transactions.
3. The ideal method to represent the sales ledger data in your company accounts program depends on your requirements and the accounts package you have.
If you have a standard small-business accounts program (such as Sage Instant Accounts/One accounting/Quickbooks/Xero) then:
Use LabManager's CSV Exporter to export summarised transactions (ie. summary invoices). Manually allocate customer's credits to debits.
Manually enter one invoice summary total for each customer, for each month. Enter all payments in LabManager and your accounts program as they occur. Manually allocate customer's credits to debits.
If you have a large accounts program such as Sage Line50/ 200, Access Accounts, and for some reason you require individual invoice transactions to be available then:
Use the CSV Exporter to export all transactions to the accounts program.