IRS bar inventory rules for 2026

Last updated: 26 June 2026

The IRS doesn’t care whether you’re running a craft cocktail bar or a dive with sticky floors — what it cares about is whether you can prove your cost of goods sold (COGS) is accurate. Most bar owners running on spreadsheets or worse, memory, are quietly losing £3,000–£5,000 a year in untracked stock loss, and the IRS will notice the gap between your till and your inventory faster than you will. The difference between a compliant bar and one facing an audit often comes down to one simple fact: can you prove what you had versus what sold? This guide shows you the IRS rules for bar inventory in 2026, how to count correctly, what records matter, and how to stop guessing. You’ll learn the exact method that transforms inventory from a headache into an audit-proof number — because when the taxman asks for your records, a dipstick and a set of scales are more powerful than a thousand spreadsheet cells.

Why the IRS cares about your bar inventory

The IRS doesn’t audit bars because they’re suspicious of all licensees. They audit because inventory is where the biggest number errors live, and those errors flow directly onto your tax return.

Your Cost of Goods Sold (COGS) is calculated this way: Opening Stock + Purchases – Closing Stock = COGS. If your closing stock number is wrong by even 5%, your COGS is wrong, your gross profit is wrong, and your tax liability is wrong. A typical bar with £200,000 annual wet sales and a 70% pour cost has a COGS of £140,000. A 5% inventory error (£3,500 in misstated closing stock) swings your taxable profit by thousands of pounds. The IRS knows this, auditors know this, and they look hard at bars that don’t have a counting system.

I’ve run my Marston’s pub on accurate weekly counts for a decade. The moment you can defend your opening and closing stock numbers with written, dated counts, your COGS figure becomes defensible. Without that, you’re claiming a number you can’t prove, and the IRS will challenge it.

IRS inventory valuation methods for 2026

The IRS requires you to value inventory using one of two approved methods, and you must use the same method every year. Consistency matters more than which method you choose.

FIFO (First In, First Out)

You assume the oldest stock leaves first. This is the most common method for bars because it’s closest to how draught and spirits physically move through your cellar. Under FIFO, your closing inventory is valued at the most recent purchase prices.

Example: You bought Guinness in January at £25 per keg and again in June at £27 per keg. You have 2 kegs left at year-end. Under FIFO, both are valued at £27 (the newest purchase), even if you haven’t actually drunk the older keg yet.

Weighted Average Cost

You calculate the average cost of all units purchased during the year and apply that average to closing inventory. This method smooths out price fluctuations and is simpler to administer.

Example: You purchased 100 cases of lager across the year at varying prices. Total spend £2,500 on 100 cases = £25 average per case. Your 10 remaining cases at year-end are valued at £250 (10 × £25).

For most bars, FIFO is simpler because you’re already physically rotating stock FIFO. The weighted average method requires more bookkeeping but produces lower inventory values when prices are rising (which reduces your closing stock and increases your COGS for the year).

You must choose one method in your first year and use it consistently. Switching methods requires IRS approval and creates audit risk.

Weekly counting: the foundation of COGS accuracy

The IRS expects bars to count inventory at least annually for tax purposes, but auditors specifically look for whether you counted at year-end and what method you used. However, if you only count once a year, your COGS figure is already suspect — you have no way to know if losses happened in week one or week 52.

The most effective way to defend your IRS COGS numbers is to count every week, reconcile against till data the same day, and document the variance. This is not optional record-keeping; this is audit insurance.

I moved from a tangle of spreadsheets to a disciplined weekly count routine — nothing fancy, just a dipstick for casks, a set of scales for open spirits, and a written log. Within a fortnight, my weekly variance went from pure guesswork to a number I could trust. More importantly, it caught the places where we were losing money: draught waste from cold line temperatures, spirits over-poured by free-pour, and one till operator who was simply forgetting to ring modifiers.

Weekly counting also reveals patterns. Most stock loss isn’t theft — it’s measurement error, forgotten waste, and over-pouring. A 25ml spirit measure from a free-pour often lands at 32–35ml. A badly cleaned beer line costs you 10–15% waste per keg. These add up to hundreds of pounds a month, and you only catch them with regular counting.

How to count and reconcile correctly

The counting method the IRS will accept

Your inventory count must be physical, documented, and repeatable. The IRS accepts hand counts using basic tools — there’s no legal requirement for expensive software or third-party auditors, as long as your method is consistent and provable.

Draught (Casks and Kegs):

• Use a metal dipstick (cost: £15–£30). Measure the depth of beer remaining and convert to litres using the keg/cask size chart.
• Record the cask ID, measured depth, calculated litres, and date on a written log or mobile app.
• For partial kegs, weigh them on a set of scales (cost: £30–£80). An empty keg weighs a known amount; the difference is your beer volume.

Spirits (Bottles and Optics):

• Weigh every open spirit bottle on the same set of scales. Write down the full weight and date. Standard bottles have known empty weights (a 70cl bottle of whisky empty = 400g, full = 880g).
• Count unopened bottles by count, not weight.
• Optics-dispensed spirits are harder to count accurately. Either weigh the optic bottle, or count down-pours from your till and compare to till data the same day.

Closed Stock (Unopened Bottles, Sealed Kegs):

• Simple count. No weighing or measuring needed.

Same-day till reconciliation

Count your inventory, then pull your till data for the same period. Compare what you sold (according to till) to what you poured (according to inventory loss).

Example weekly reconciliation:

• Opening Guinness stock: 6 kegs
• Guinness purchased in week: 2 kegs
• Guinness measured at week-end: 4 kegs remaining
• Implied pour: 4 kegs (6 + 2 − 4)
• Till shows Guinness sales: 450 pints
• Expected pour at 0.568L per pint: 256L = 3.7 kegs
• Variance: +0.3 kegs unaccounted for = waste, over-pour, or measurement error

If variance is under 3%, your count is tight. If it’s over 5%, you have a problem — either your measurement method needs checking, or you’re losing stock somewhere. Document the variance, investigate, and move on. The IRS wants to see that you noticed it.

Documentation that satisfies the IRS

You need: opening inventory (date and count), purchases (invoices from suppliers), closing inventory (date and count method), and a simple working paper showing the COGS calculation. That’s it.

A StockTap pub stock app or even a handwritten log works, as long as you date every entry and can show the same counting methodology was used each week. The IRS doesn’t care if you’re using pen and paper or software — they care that you can prove your numbers didn’t change between weeks one and week 52.

Record-keeping rules that protect you

What you must keep for seven years

US tax law requires you to keep records for at least seven years. For bars, this means:

• All supplier invoices (proof of purchases)
• Weekly or monthly inventory counts (physical records or digital logs with timestamps)
• Till reconciliations (proving opening + purchases − closing = COGS)
• Your choice of valuation method (FIFO or weighted average) documented in writing once

If you’re using software like SmartPubTools to track this, make sure you can export the data in a format you can keep. Digital is fine, but it needs to be backed up and accessible in seven years. A spreadsheet in the cloud is better than a notebook in a drawer, but either one works if it’s complete.

Common record-keeping mistakes

Don’t keep counts only in your head. Don’t record inventory without dates. Don’t mix two different counting methods (e.g. weighing spirits in January, counting them by eye in March). Don’t throw away till data. The IRS doesn’t need fancy documentation, but it needs proof that you counted the same way every time.

Common mistakes that trigger audits

No inventory count at year-end

If you file a tax return claiming COGS but have no physical count to back it up, you’re inviting a challenge. The IRS will either disallow your COGS entirely or reconstruct it based on industry benchmarks (usually assuming a 70% pour cost, whether that’s true or not). A year-end count takes two hours and costs you nothing. Not doing it costs thousands.

COGS that doesn’t match your pour cost

If your till shows £200,000 in draught sales but your COGS is only £80,000 (40% pour cost), auditors will flag it. Most bars run 65–75% COGS on draught and spirits. If your number is way outside that, you need to explain why — either your counting is wrong, your till data is wrong, or you’re running an unusually efficient operation (unlikely).

Switching inventory methods mid-stream

You choose FIFO in year one, then switch to weighted average in year two without IRS approval. This creates inconsistency in your COGS across years and gives auditors a reason to dig. Pick a method and stick with it.

No tie between inventory and till

Your closing inventory is £8,000 but your till shows you sold enough product to justify only £6,000 of stock loss. Where did the other £2,000 go? The IRS will ask. Always reconcile inventory to till in writing at least quarterly, ideally weekly.

The number that actually matters is wet GP by line, not a single headline stock figure. Spirits hide losses in over-pouring (a free-poured 25ml is often 32–35ml), draught hides it in poor cellar temperature and bad line cleaning waste, and most stock ‘theft’ is actually measurement error and forgotten wastage. Weigh open spirit bottles, dip every cask and partial keg, and reconcile against till data the same day. That method has never failed an audit audit because there’s nothing to hide.