In Sage, Help, search Import. Import/Export Tips:

All Maintenance records will be overwritten. Inventory Assemblies may not override on import due to incorrect Revision Number.

When importing journal transactions, you may encounter duplicate reference numbers/check numbers between existing records and the new records you are importing. In many cases, you can choose to skip the record with the duplicate reference or cancel the process. If you skip the record, it will not be imported. If you cancel the process, only records up until that point will be imported.

There are certain situations in which Sage 50 does not allow duplicate reference numbers. In this case, you must manually enter these records or values.

Sage 50does not allow duplicate references in the following situations:

• Sales: You cannot have a duplicate invoice number for the same customer ID.
• Purchases: You cannot have a duplicate invoice number for the same vendor ID.

Duplicate reference numbers are allowed in the following situations:

• Payments (Cash Disbursements): you can have a duplicate check number. You will be given a warning message allowing you to reuse the same number or cancel.
• Receipts: you can have a duplicate reference number. If you selected the Warn if Duplicate Reference check box in the template and you have a duplicate reference number when importing, you will receive a warning message that a duplicate reference number exists for the same customer ID. You can click OK to import the record with the duplicate reference number, No to skip the record, or Cancel to halt the process. If you cancel, all records up until that point will be imported.
• Payroll: You can have a duplicate check number. You will be given a warning message allowing you to reuse the same number or cancel.