QuickBooks Desktop does not import QIF files directly. If your bank, credit card company, or accounting software provides transactions in QIF format, you need to convert them to QBO format first.
Use the ProperConvert app to convert QIF to QBO on Windows or macOS.

Before converting, you need to set three values in ProperConvert:
Account ID must be digits only. Use your actual account number or any number you choose. Use the same Account ID each time you convert files for the same account. Use a different Account ID for each separate account.
Account Type must match the account in QuickBooks you plan to import into. QuickBooks only allows a QBO file created for a checking account to import into a checking account, and a QBO file for a credit card to import into a credit card account.
INTU.BID is the bank label shown during the QBO import in QuickBooks. Search for your bank in the lookup list. Make sure the bank you select supports your Account Type. If your bank is not listed, use the default value (3000 - Wells Fargo) - QuickBooks accepts it.
Currency should be USD for the QuickBooks US edition even for non-USD accounts. For the Canadian edition, use USD or CAD. For the UK edition, use GBP.
Before importing, make sure the account in QuickBooks is not connected to online banking. If it shows a yellow icon in the Chart of Accounts, you need to disconnect it first: right-click the account, choose Edit Account, click Bank Feed Settings, and select Deactivate All Online Services.
To import:
Before importing, make sure the account is not connected to online services. If it shows a blue ball icon in the Chart of Accounts, right-click the account, choose Edit Account, click Online Settings, and set it to Not Enabled.
To import:
QIF (Quicken Interchange Format) is an older file format for financial transactions. Banks, credit card companies, and personal finance software like Quicken use it to export transaction data. QuickBooks Desktop cannot import QIF files directly, which is why a conversion to QBO is needed.
QuickBooks Online does not support QBO file imports from outside sources. It only accepts CSV files through its bank upload feature. If you need to get QIF transactions into QuickBooks Online, convert the QIF file to CSV using ProperConvert and upload that CSV file through the QuickBooks Online banking section.