Hi Julia,

When importing bills with multiple line items make sure the bill has the same bill.no and, in the Line Tax Code choose the the correct GST for each line like GST on purchases. Then, on the mapping stage in QBO, decide if it's Exclusive or Inclusive of Tax in the Line Amount.

You can also download the sample file when importing bills for reference. And check this link to learn more about: Import your bills in QuickBooks Online.

If the issue persist, I recommend contacting our Customer Care Team. That way, our care agent can check your CSV file and help you format it.

Post again in the Community if you have questions about importing data in QuickBooks.