Inventory costing after a Desktop-to-Online conversion: average cost to FIFO, and when Form 3115 enters the picture

Of everything that moves in a Desktop-to-Online conversion, inventory is the one that surprises people most, because the converter isn't making an error. It's doing exactly what it's designed to do, and the result is still different numbers. If you carry inventory, this is the part of the tie-out you can't skip.

Why the numbers change at all

QuickBooks Desktop (Pro, Premier, and Enterprise without Advanced Inventory's FIFO option) costs inventory at weighted average. Every receipt recalculates the average cost of the item, and every sale relieves inventory at that average.

QuickBooks Online, for most of its life, costed inventory at FIFO only. Intuit's current help documentation now describes two options, FIFO and Moving Average Cost (Intuit's name for weighted average), with two important conditions: the method is chosen when inventory tracking is first turned on, it can't be changed afterward, and if any inventory item exists before the choice is made, the file defaults to FIFO. Whether a Desktop-to-Online conversion lets you pick average cost, or creates the items first and locks you into FIFO, is a question to settle with Intuit's migration documentation (or a test conversion) before you run the real one. If you can keep average cost, the revaluation below largely goes away.

Assume the common case, a converted file on FIFO. The conversion tool can't carry the average-cost history. Instead, it establishes an inventory start date (generally the conversion date, or the date you specify) and rebuilds each item's cost layers on the FIFO basis from there. Intuit's own documentation on what converts says inventory comes across as quantity and value as of the start date, recalculated under FIFO, and that historical transactions before that date may be adjusted. Which means:

• Inventory asset on the converted balance sheet can differ from Desktop, sometimes materially, if your items have had cost swings.
• Cost of goods sold on prior periods can shift, because the relief on each historical sale is recomputed with FIFO layers instead of the average that existed at the time.
• The difference lands somewhere. Usually in Opening Balance Equity, sometimes in a conversion adjustment to COGS or inventory, depending on the version of the tool. Either way it has to be found and explained.

A worked example

Say you stock one part. You bought 100 units at $10 in January, 100 at $14 in March, and sold 120 by the end of April.

One part, a $160 swing. Multiply by a few hundred SKUs with real price volatility and the variance is the biggest single line on the tie-out. In a rising-cost environment FIFO shows lower COGS and higher inventory than average cost; in a falling-cost environment it's the reverse.

How to tie inventory out after the conversion

The standard is the same as everywhere else in a converted file: every variance identified and documented, not zero by accident.

1. Pull both inventory valuation reports as of the conversion date. Desktop: Inventory Valuation Summary. QBO: Inventory Valuation Summary. Export both to a spreadsheet and match on item.
2. Confirm quantities first. Quantity on hand should match exactly, item by item. If quantities differ, the problem isn't costing; it's a transaction that didn't convert, a negative-inventory item the converter couldn't layer, or an assembly that came across as a plain item. Fix quantities before you look at a single dollar.
3. Then compare value. With quantities matched, every dollar difference is the costing method. Document the total variance by item, and total it. That number is your average-to-FIFO revaluation.
4. Find where it landed. Look at Opening Balance Equity and at COGS in the conversion period. The revaluation went into one of them, and your working paper should show which.
5. Decide what to do with it. For the books, most practitioners post a documented adjustment that moves the revaluation out of OBE into retained earnings or a labeled "inventory method change" equity line, so OBE goes to zero and the balance sheet still ties to supporting detail. See clearing Opening Balance Equity.
6. Reconcile COGS for the year to date. If the conversion happened mid-year, the P&L for the year is now part average cost (before) and part FIFO (after). Note the break point in your working papers; the preparer will need it.
7. Sign it off and move on. Record the method, the date, the total variance, and where it was posted. That one page is what you'll hand the preparer and, later, anyone who audits the file.

Watch for these in the item list

• Negative inventory. Any item that went negative in Desktop at any point has no clean FIFO layers to build from. The converter does its best, and "its best" is where most of the unexplainable variances come from. Clear negative inventory before converting.
• Inventory assemblies. Desktop assemblies (Premier and Enterprise) convert to regular inventory items in QBO, which has no assembly feature. Built assemblies become a quantity of the finished item; the bill of materials is lost. Export it before you convert.
• Items with zero cost. Items that were never received through a bill or item receipt, just adjusted in, may carry no cost at all. They'll convert at zero and understate inventory.
• The costing-method choice itself. If Intuit's current tooling offers Moving Average Cost on conversion and your Desktop file is on average cost, choosing it is the single biggest simplification available. Confirm before converting; the choice is permanent once transactions post.
• Units of measure and multiple locations. Enterprise's Advanced Inventory features (sites, bins, lot and serial numbers) don't convert. If you rely on them, the question isn't how to tie out; it's whether to convert at all.

The tax question: is this a change in accounting method?

Here's the part that catches owners. For tax purposes, the inventory costing method you use is a method of accounting, and changing it generally requires IRS consent via Form 3115, Application for Change in Accounting Method. Switching from average cost to FIFO is a recognized method change, and for many taxpayers it falls under the automatic consent procedures, meaning you attach the form to the timely filed return for the year of change and file a copy with the IRS, rather than requesting advance approval. The automatic procedures also typically require a Section 481(a) adjustment, which is the cumulative difference between the old and new methods as of the beginning of the year of change, spread over the period the rules prescribe.

Three things to be clear about:

• Converting your software is not the same as electing a tax method. Your tax return reports inventory on the method you've been using. If the books now say FIFO and the return says average cost, your preparer has to reconcile the two every year, or file to change.
• Small taxpayers may have more room. Businesses under the gross receipts threshold for the small business taxpayer exemption (indexed annually, in the low tens of millions) can use simplified inventory methods under Section 471(c), which changes the analysis entirely. Whether you qualify, and whether you've already made that election, is a preparer question.
• The year of change matters. The method change is tied to a tax year, not the conversion date. Converting in July doesn't make the first half of the year FIFO.

None of this is a reason to avoid converting. It's a reason to put "inventory method change" on the preparer's list before the first return on the new file, with your tie-out working paper attached, so the Section 481(a) adjustment is computed from real numbers instead of reconstructed ones.

The controller's rule: the inventory variance on a conversion is never zero and never a surprise. If your tie-out shows zero on inventory with cost history, look again.

Inventory is one row of the tie-out. The full sequence, cash through Opening Balance Equity, is in why your converted file doesn't tie out, and the reference table of what does and doesn't convert is in what transfers from Desktop to Online.

Common questions

General guidance on inventory accounting after a software conversion, not accounting, tax, or legal advice. Inventory method changes carry tax consequences and specific filing requirements; confirm your situation with your tax preparer before filing.