It is a known bug in QB that an improper IIF file produces no errors. Instead it shows all is fine, but the transactions are not imported.

>Not sure if it's that way in your actual file, but in your post the word MEMO is misspelled on the 2nd line. If that's not it, verify the number of fields matches the definition, including trailing tabs for the unused DOCNUM and MEMO fields. This article http://www.ita-software.com/papers/QuickBooks.htm might be helpful.
>
>>Has anyone tried to interface an app into QuickBooks using an IIF file? I am trying to create an IIF file that will be
>>imported into QuickBooks Premium edition and create a general journal entry. It keeps saying the file has been
>>imported but the data is not there. File follows
>>
>> !TRNS TRANS TRANSTYPE DATE ACCNT CLASS AMOUNT DOCNUM MEMO
>> !SPL SPLID TRANSTYPE DATE ACCNT CLASS AMOUNT DOCNUM MDMO
>> !ENDTRN
>> TRNS GENERAL JOURNAL 10/21/15 ACCOUNTS RECEIVABLE-WATER 226.90
>> SPL GENERAL JOURNAL 10/21/15 PREMIER BANK -136.90
>> SPL GENERAL JOURNAL 10/21/15 BAD CHECK CHARGE -90.00
>> TRNS GENERAL JOURNAL 10/21/15 METERED SALES 23.40
>> SPL GENERAL JOURNAL 10/21/15 ACCOUNTS RECEIVABLE-WATER -23.40
>> TRNS GENERAL JOURNAL 10/21/15 ACCOUNTS RECEIVABLE-WATER 150.00
>> SPL GENERAL JOURNAL 10/21/15 NEW SERVICE/TRANSFER FEES -150.00
>> ENDTRNS
>>
>>There is a blank spaced field for the Class field between the Account and the Amount fields. If anyone has any experience in
>>this I would appreciate any advice.
>>
>>Thanks in advance,
>>
>>Brad