There are a few reasons why one would want to combine different companies into one data file in QuickBooks. One reason would be in the opening of a new location for the same business which is organized under a different LLC than the first. Another would be that you have purchased another business that uses QuickBooks and want to have both on the same file. One way to handle this involves purchasing third-party software to handle the merge, the other is in the use of the class feature of QuickBooks.
Items you will need
Company files to be merged
Data Transfer Utility software
Combining Companies in QuickBooks
Choose which option is best for you. The choices are: purchasing the Data Transfer Utility Tool or manually enter the changes.
Turn on the Class Feature in Quickbooks. Go to the Menu bar and click "Edit." Scroll down and click "Preferences." When the Preferences window pops up find and click on "Accounting - Company Preferences." Check the boxes next to "Use Class Tracking" and "Prompt to Use Class Tracking."
Use the Class feature. If you are in the position of wanting to combine two companies that are just starting out, whether it's because it is two different locations, for example, combine the two using the Class feature of QuickBooks. Create a class named ABC Company and another named XYZ Company. You do this by going to the Item menu and clicking on Class Item menu. Click CTRL + N and enter the name of the class (ABC Company) in the uppermost box and click "OK." Repeat this for the other company and you can begin to assign each transaction, whether it be expense or income, to one of the two classes. This feature allows you to view combined reports or individual reports of the companies.
Use report totals from previous files. If you have numerous transactions print the profit and loss and balance sheets from the company to be merged. Use the class tracking to assign each transaction to the original company. Assign each transaction by clicking on the desired company in the column next to the transaction.
Create a general journal entry to reflect the totals on the reports printed from the new company and assign them to a class designating them as new company transactions. Each transaction will now have a "class" column you can use to designate it for the ABC or XYZ companies.