1099-K duplicates income included elsewhere in my bookkeeping spreadsheet

[iC4U]

I have a 1099-K from eBay, the source of most of my sales income. However, I do have lesser amounts from other sources. My bookkeeping spreadsheet, which has evolved over 2 decades of changes in eBay and elsewhere, includes ALL my sales. My system is set up to account for eBay Payouts, customer paid and actual shipping costs (not always exactly the same), consignment payouts, and occasional sales State Sales Tax payments.
If I enter the 1099-K amount in TurboTax, then I can't use the "income" amount from my spreadsheet, as that will duplicate MOST of the sales income! Is there any way to sort this out, aside from building a new bookkeeping system from scratch to separate eBay from everything else? It is all ONE business with shared expenses, so how do I fill out Schedule C without including eBay payments??

[RobertB4444]

You will enter the 1099-K income and then enter the income from the other sources separately so that your total income matches what is on your sales spreadsheet.  You can enter the other income as sourced from cash sales or however you have it recorded.

@iC4U 

[iC4U]

Thanx, but that still means I have to revamp my whole bookkeeping system. Some of the eBay income may be from consignments, which means I have to deduct those payments - but I can't just deduct all consignment payouts, because some of them might NOT be from eBay... It still sounds like I am going to have to make up a whole new records system (or TWO) - within the next 2 weeks - in addition filing my income tax AND quarterly Sales Tax. Not a welcome development. 

Isn't there some other way? What I have been doing the past few years, while 1099-K forms were being issued, but NOT REQUIRED, was fine and accurate - but now that is invalid? I have to redo my whole system around this redundant form?

[ThomasM125]

If you know what your net income is, then you can back into the sales figure. You just need to enter the 1099-K form amount, then all of your expenses. Then look at your net income and subtract that amount from your actual net income and the difference goes to sales. If your sales are short, add the difference to income from cash sales. If your income is overstated, enter a cost of goods sold amount categorized as "consignments" or a similar category.