As a QuickBooks ProAdvisor, I have seen all of the "disaster" scenarios, including:

• A client's computer crashes. The computer's hard drive is toast and they can't recover their QuickBooks Desktop (QBD) company file. To make matters worse, for some reason or another, they don't even have any recent backups.
   

• A client using QuickBooks Online (QBO) connects and syncs transactions from a third party POS app. However, deposits are added to income accounts with more detail via downloaded transactions in Banking instead of matching to imported deposits. A duplication of income and a mess of unneeded transactions persist for months to years.
   

• A client who never used QuickBooks before gets audited by the IRS. All of the sudden, they need years of data in QuickBooks so that correct financial statements can be generated.

While this news is always heartbreaking for me, it is worse for my client having to make the decision to work with an old backup and catch up or start fresh with a new QuickBooks company file. Or for the QuickBooks Online client to decide between fixing existing data or creating a new account, these are not easy decisions to make.

Fortunately, I have tools that can help my clients no matter what recovery plan we agree upon. Using the Bank Feeds in QBD or the Banking center in QBO, the processes of adding hundreds of historical transactions becomes painlessly feasible. However, some banks may only allow downloading 90 days to 6 months or a year of transactions from their online banking websites. Or they may not even offer a .QBO (QuickBooks Web Connect) file download, the only type that can be imported into QBD. 

The way around this limitation is to use bank statements, either filed paper statements or downloaded PDFs. These can be converted to .QBO files and imported into QuickBooks. Using bank rules, the process of categorizing and adding transactions can be sped up. And with QBO, you can even have bank rules that

automatically

add hundreds of transactions that match a bank rule. 

For more complex cleanup situations, it is possible to delete hundreds to thousands of erroneous transactions. Or it may be necessary to export certain transactions from one account/file, to be imported into another QBO account or combined with another file.