Use Quickbooks compatible formats (QBO or IIF)

QuickBooks accounting software is offered as QuickBooks Desktop (QBD) or QuickBooks Online:

QuickBooks Desktop: the QBO format (up to three years old) and IIF format.
QuickBooks Online: the OFX/QBO/QFX format and the CSV format.

Use the ProperConvert app to convert your file to a format compatible with Quickbooks.

Import into QuickBooks through the QBO format

The QBO format is a QuickBooks Web Connect format used to import bank transactions into QuickBooks (under Bank Feeds). ".QBO" does not mean "QuickBooks Online".

Banks and credit card companies provide QBO files to download transactions. QBO files have account details like account id, bank id, currency, ending balance, and date. QBO files have the following transaction details:

date.
amount.
payee.
description.
check number.
unique transaction ID.

QuickBooks imports .QBO files under Bank Feeds. Banks do not know your accounting setup, so QBO files have no category or account details. After import, QuickBooks matches transactions to vendor records and expense/income accounts.

Import into Quickbooks Online

QuickBooks Online (except Self Employed) imports QBO files (OFX and QFX as well).
QBO (and OFX and QFX) is the best format for QuickBooks Online. It imports the most details: date, amount, payee, memo, check number, and a unique transaction ID to prevent duplicates.
QuickBooks Online (including Self-Employed) also imports CSV files, but only date, amount, and description.

Import into QuickBooks Desktop through the IIF format

IIF works with all QuickBooks versions. It lets you include more details like expense/income accounts and classes. Unlike QBO, which lets you match records after import, IIF requires vendor and account names to match exactly what is in QuickBooks. If they do not match, QuickBooks creates new records.

Quickbooks Online does not import IIF files.

IIF is a system-level format. QuickBooks imports it directly into its database, so your data must be exact. Typos and mismatches create new vendor records and accounts. Always back up your QuickBooks company file before importing IIF. If you are new to QuickBooks, start with the QBO format instead.

Intuit created IIF for QuickBooks. Many apps export in this format for transactions, receipts, bills, invoices, and other data. IIF data goes directly into the QuickBooks data file.

For transactions, IIF format supplies the following details:

date.
amount.
vendor or customer[:job].
description.
main account.
expense/income account.
class.

Vendor names and account names must match exactly what is in QuickBooks. All QuickBooks Desktop versions support IIF import. QuickBooks Online does not. For QuickBooks Enterprise, the user must have exclusive access to import IIF files.

Use the ProperConvert to convert your transaction files to the IIF format.

What are the main differences between QBO and IIF import into QuickBooks?

QBO import needs an internet connection. IIF import is fully offline.
QBO lets you apply renaming rules to match payees and assign accounts after import. IIF requires exact account names up front. ProperConvert lets you set a default expense account for IIF.
QBO transactions land in the Online Banking Center first. You review, match, and then accept them into the register. IIF imports go directly into the register.
QBO import requires QuickBooks to be no older than three years. IIF works with any version.
QuickBooks Online imports QBO files only. It does not import IIF files.

Learn More

QBO - What is QBO (web connect) format
QFX - What is QFX file/format and how to open it?
OFX - What Is OFX File Format and How to Open it?
IIF - What Is IIF File Format and How to Open it?
QuickBooks Desktop - How to Import Bank Transactions into QuickBooks Desktop