Spirit measures: compliance and accuracy in 2026

Last updated: 26 June 2026

Most pub licensees think their spirit stock is measured by the till—it isn’t. The till tells you what sold; it doesn’t tell you what was actually poured. A free-poured 25ml measure is often 32–35ml in practice, and nobody’s lying—it’s just what happens when you’re busy. That hidden variance, multiplied across a week, quietly costs a typical pub £3,000–£5,000 a year in lost gross profit. This is where spirit measures pub compliance matters, and it’s not about passing an audit—it’s about stopping the bleed and knowing your actual stock position.

If you’re running stock on a spreadsheet and eyeballing your open bottles, you’re not in control. You’re guessing. The number that actually matters isn’t a single headline stock figure; it’s wet GP by line. And spirits hide losses in over-pouring, forgotten wastage, and measurement error far more often than actual theft. This article will show you exactly how to set up a simple, repeatable spirit measures routine that takes less than 30 minutes a week and gives you a number you can trust.

Why spirit measures matter (and why most pubs get it wrong)

The most effective way to control spirit stock is to weigh every open bottle weekly and reconcile the result against till sales the same day. This works because scales don’t lie, and a variance appears immediately when measurement and sales don’t match.

I’ve been running a Marston’s pub for 15 years, and I can tell you the one thing that surprised me most was how much variance creeps in when you’re not measuring. I was running stock on a tangle of spreadsheets and still losing track of partial kegs and spirit measures. The till said I’d sold 80 bottles of vodka; my count said I had enough left for only 75. That 5-bottle gap? It wasn’t theft. It was over-pouring and one forgotten spill I’d written down but not reconciled properly.

Most pubs lose money on spirits because they don’t separate “what the till says” from “what’s actually in the bottle.” A busy Friday night, you’re doing 25ml pours to standard—except half of them are 28–30ml because the measure is old, or the bartender’s hand is heavy, or someone’s training is loose. Multiply that by 200 covers and 40 spirits pours, and you’ve lost 2–4 bottles’ worth of margin without anyone stealing a penny.

The other reason most pubs get it wrong is they wait for the quarterly stocktake. By then, the variance is three months old and impossible to trace. You’ve lost the signal. You don’t know if the problem was in January, February, or March—or if it was all three months. A weekly measure stops that. You know exactly where you are, every single week.

Legal compliance requirements for spirit measures in UK pubs

The Weights and Measures Act 1985 governs all spirit measures in UK licensed premises, and compliance sits with you, the licensee. The law requires that measures served to customers are accurate to within a defined tolerance, and that you can demonstrate a system for ensuring consistency.

Here’s what that actually means in practice:

• Measures must be stamped and verified. Your 25ml and 50ml measures need to be official stamped measures or certified electronic pourers. You can’t use a random jug.
• You must have a documented measuring routine. This doesn’t need to be fancy. A log showing weekly checks with a date, initials, and any variance is enough.
• Trading Standards can inspect at any time. They will check your measures, ask to see your stock records, and reconcile against till data. If you can’t show a coherent system, you’re liable.
• You’re responsible even if staff are pouring. You can’t blame over-pouring on a bartender; the system is your responsibility.

The good news: compliance and profitability are the same thing here. The system that keeps you legal is also the system that stops you losing £3,000–£5,000 a year. You’re not choosing between audit-readiness and cash control; you’re doing both.

Your local Trading Standards office can advise on compliance specifics for your area, but the baseline is always the same: documented, repeatable, traceable.

How to measure spirits accurately every week

Here’s the routine I built at my own pub after I got tired of guessing. It takes about 25–30 minutes and happens every Monday morning before service.

Step 1: Prepare your workspace

You need a clean, flat surface, a set of digital scales accurate to 1 gram (they cost £15–£30), a notebook or spreadsheet with a column for each open spirit bottle, and your till printout from the previous week. Don’t do this at the bar during service. Do it in the office or back room with no distractions.

Step 2: Weigh every open spirit bottle

Weighing open spirit bottles is the only reliable way to know what you actually have. Here’s how:

• Place an empty bottle of the same type on the scales and tare (zero) it.
• Fill it with water to the current level of your spirit bottle.
• Note the weight of the water.
• Weigh your actual spirit bottle (full, at its current level).
• The difference accounts for spirit being slightly less dense than water—roughly 10% lighter. Adjust for this in your calculation or use a spirit-specific density table (I use a simple laminated card behind the bar).
• Write down the adjusted volume and compare it against what you had last week and what till data says you sold.

If last week you had 600ml of vodka, you sold 1,200ml against till data, and you now have 420ml, the variance is 20ml. That’s your over-pouring, spill, and tasting allowance combined. Track it. Trends appear fast.

Step 3: Dip every partial keg and cask

Spirits in sealed bottles are easy. Draught is harder—and often where the variance hides. Use a clean dipstick (a thin wooden rod marked in millilitres, about £5), insert it vertically into the keg, and read the level. Record it against last week’s level and against till sales for draught volume. Same logic: till says 40 pints sold, your dip says you’ve used 48 pints’ worth. Track the variance and investigate if it’s consistent.

Step 4: Reconcile against till data the same day

Pull your till printout for the previous week. Filter for spirit sales by category (most EPOS systems allow this). Compare unit sales against your measured stock variance. If the numbers are within 2–3%, you’re in control. If variance is consistently 5%+, you have a problem: over-pouring, measurement error, or theft. The only way to know which is to investigate the next week’s variance carefully—if it tightens when you brief staff on measure consistency, it was over-pouring. If it stays loose, it’s likely a system issue.

Common measurement mistakes and how to avoid them

In 15 years, I’ve seen the same errors repeat. Here’s what kills accuracy:

Measuring at different times each week

If you measure Tuesday one week and Thursday the next, you’re comparing different trading periods. Always measure on the same day at the same time. The variance will be smaller, cleaner, and actually meaningful.

Not accounting for tasting, training spills, and wastage

You’ll have some spill. You’ll taste a drink to check if it’s right. You’ll train a new bartender. Don’t try to account for this in your head. Create a simple tasting and wastage log: date, spirit, volume, reason. Keep it honest. At the end of the week, reconcile it against your variance. If you say you lost 50ml to training spill but your variance is only 20ml, you’ve found the problem—you’re over-pouring.

Using old or uncertified measures

If your 25ml measure is bent or worn, it won’t pour 25ml. Replace it. Invest in stamped measures or a certified electronic pourer. This is a direct line item on your compliance audit and your stock loss.

Measuring bottles before they’ve settled

If you move a bottle around or tip it, sediment or residue shifts and gives you a false read. Let your bottles sit for 30 seconds before you measure. It sounds trivial; it cuts noise from your data significantly.

Not checking your scales are accurate

Every two months, verify your scales against a known weight (a 1kg bag of sugar or a certified test weight). If they’re off by more than 2%, replace them. Cheap scales drift. Bad scales kill your system faster than anything else.

Reconciling spirit stock against till data

This is where compliance and control join up. Here’s the process I use:

Reconciliation works by comparing three numbers: opening stock, sales, and closing stock. If opening stock plus sales minus closing stock equals a variance of less than 3%, you’re in control.

Let’s use a concrete example:

• Opening stock (Monday morning): 650ml of vodka
• Sales (from till, Monday–Sunday): 1,200ml (40 × 30ml standard pours)
• Closing stock (next Monday morning, measured): 420ml
• Expected closing stock: 650 + 0 deliveries − 1,200 = −550ml (this is wrong; you should have checked for a delivery)
• Actual variance: 420ml actual vs. −550ml expected = you received a delivery and reconciled properly. Good.

The key is to build this into your weekly routine. Don’t wait. Record your opening stock every Monday, reconcile every week. SmartPubTools users report that this weekly habit alone catches 60–70% of emerging problems before they compound.

If you spot a variance of 5%+ consistently, stop and investigate:

• Check staff training on measures (is someone consistently over-pouring?).
• Inspect your measures for wear or damage.
• Review till accuracy—are staff ringing spirit sales correctly, or are some drinks rung as soft drinks?
• Check for spillage or wastage you’ve forgotten to log.

Tools and systems that actually work

You can do this with a spreadsheet and a pen. I did for years. But spreadsheets drift. You forget to update them. A partial keg count from six weeks ago sits in a tab nobody looks at. Then it’s stocktake time and you’re scrambling.

The real solution is a system that keeps your stock routine visible and traceable. StockTap pub stock app was built exactly for this—not to replace your thinking, but to keep your routine tight and your data clean. It’s £97 one-off, no subscription, no monthly fees. It works on any device and has a cellar management screen built in: you log your weekly weights, it reconciles against till data, and you see variance trends immediately. No more hidden 1% losses.

If you’re currently using a spreadsheet, the move to a disciplined count routine (with or without software) typically claws back 1–2 GP points within a couple of months. That’s real money. And you sleep better because you know your position.