QuickBooks Online stock costing: FIFO or average, and a choice you cannot undo
QuickBooks Online values stock on FIFO or moving average and the method cannot be switched, so here is how to check yours and what to do if it is wrong.
Questions about stock valuation keep surfacing among QuickBooks Online users who sell physical goods. We reviewed the guidance published for the United Kingdom edition, which sets out the two costing methods in plain terms. It also carries a warning that catches new users out. Once stock activity begins, the costing method cannot be changed.
Two methods, and a choice that sticks
The software costs stock one of two ways. First In, First Out, or FIFO, treats the oldest units bought as the first ones sold. Moving Average Cost, or MAC, blends every purchase into one running figure that rises and falls with the prices you pay.
One point of confusion deserves settling first. For years the software costed stock at a single average, with no setting to change it, and many plans still work that way. The two-method framework belongs to subscriptions running the newer stock engine, where FIFO appears alongside the default. If your plan lacks that engine, there is no choice to make, and none to miss.
The permanence warning is the part users overlook. Choose before the first purchase is recorded, because the books will not let you revisit the decision. That is a design choice rather than a defect. It is also why this question keeps returning to the community boards.
The widget arithmetic that shows FIFO at work
The vendor’s help article walks through a widget example, and the numbers repay a close read. Suppose you buy 20 widgets at £6 each. They sit as an asset worth £120, and cost of sales is zero. You then buy 30 more at £7 each after a wholesale price rise. Stock on hand is now 50 units valued at £330.
A customer then buys 15 widgets. FIFO costs all 15 at £6, so cost of sales rises by £90 and the asset total falls by the same amount. Five £6 units remain, alongside the 30 at £7.
The next sale, of 20 units, straddles both layers. Five come off at £6 and fifteen at £7, for cost of sales of £135. Fifteen units are left, all valued at £7. Every later sale draws from that pricier layer until it runs out.
Moving average treats the same facts differently. The two purchases blend to £6.60 a unit, so that first sale of 15 books £99 rather than £90. The gap widens whenever supplier prices move sharply. Neither method is wrong. They simply answer different questions about profit.
Which method is your company file using?
Start with your subscription, because the methods on offer depend on the plan. Plans without the newer engine run on average cost by default. Where a choice does exist, it sits among the stock settings inside Account and settings, reached from the gear icon, and it must be set before stock activity starts.
The item record gives a second check. Open any stock item from the Products and services list and read the cost figure. A single blended number that shifts after each purchase points to average cost. Layered purchase costs point the other way.
The decisive test is behavioral. Run the widget arithmetic against your own last few purchases and a recent sale. If cost of sales pulled the oldest, cheapest units first, FIFO is at work. If it pulled one blended figure, you are on average cost.
Locked in on the wrong method?
Users who find a mismatch after months of trading have three realistic paths. The engine itself stays put in every case.
If trading has barely begun, the clean fix is a fresh company file set to the right method. Do it before purchase layers build up. The cost is a few hours of re-entry, not a valuation error that compounds for years.
If the file carries real history, the engine stays. An accountant can true up the balance sheet with adjusting entries, so the asset value reflects reality. Sales will keep costing out under the original method, and internal reports will stay on that basis.
The third path is to leave the books as they are and track true unit costing outside the software, posting summary entries back in. That suits businesses with fast-moving prices, where a blended figure distorts margins badly.
Our read is that the permanence warning deserves more prominence than it gets. A method chosen in a five-minute setup window shapes every cost of sales figure that follows. Ask an accountant which method your reporting requires, and ask before the first purchase lands rather than after.