Proper discount processing prevents promotional campaigns from silently destroying your profit margins. Many restaurant owners watch their P&L deteriorate during promotional periods without understanding the underlying mechanics. Discounts aren't just marketing tools—they're revenue adjustments that fundamentally alter your cost structure.
Where discounts belong on your P&L
Discounts aren't costs—they're revenue reductions. This distinction matters more than most operators realize. Place them alongside your revenue, never with expenses.
💡 Example P&L processing:
Normal revenue: €15,000
- Discounts given: €1,500
- Net revenue: €13,500
- Food cost: €4,050 (30% of net revenue)
You calculate percentages over €13,500, not over €15,000
Impact on your food cost percentage
Here's where operators frequently stumble. Revenue drops due to discounts, but ingredient costs remain constant—your food cost percentage climbs automatically.
This is the kind of thing you only learn after closing your first month at a loss, wondering why your numbers looked solid but your bank account told a different story.
💡 Calculation example:
Dish normally €20, ingredients €6
- Normal food cost: €6 / €20 = 30%
- With 25% discount: €6 / €15 = 40%
- Your food cost increases by 10 percentage points!
⚠️ Note:
A 25% discount means your food cost percentage increases by approximately 33%. Always calculate this through before starting promotions.
Different types of promotions and their impact
Each promotion type hits your P&L differently. Here are the main variants:
- Percentage discounts: Direct revenue reduction, food cost increases proportionally
- 2+1 free promotions: 33% revenue reduction, but food cost increases by 50%
- Happy hour pricing: Lower prices during quiet hours, can compensate with volume
- Free side dishes: Extra food cost without extra revenue
Calculating your break-even with promotions
For every promotion, calculate exactly how much extra volume you need to maintain the same profit.
💡 Break-even calculation:
Formula: Extra volume % = Discount % / (100% - Discount %)
- At 20% discount: 20% / 80% = 25% more volume needed
- At 25% discount: 25% / 75% = 33% more volume needed
- At 30% discount: 30% / 70% = 43% more volume needed
Administrative processing
In your POS system and accounting, process discounts like this:
- Record the full menu price as revenue
- Record the discount as a revenue reduction (credit note)
- VAT gets calculated on the net amount after discount
- Track which promotions generate the most volume
⚠️ Note:
Some POS systems record discounts as costs. This creates an incorrect picture of your food cost and margins. Always verify your settings.
Monitoring and adjustment
Track these metrics weekly to stay ahead of promotional impact:
- Percentage of revenue from promotions (max 10-15% is standard)
- Average discount percentage
- Volume effect per promotion
- Food cost percentage during promotion periods
Systems like tools can show you the immediate impact of discounts on your food cost per dish, so you can adjust before it damages your profit.
How do you process discounts correctly on your P&L?
Record discounts as revenue reduction
Record the full menu price as revenue and the discount as a separate line 'revenue reduction'. This keeps it visible what you actually sold versus what you received.
Calculate food cost over net revenue
Always use your net revenue (after discounts) to calculate your food cost percentage. Otherwise, your food cost will appear lower than it actually is.
Monitor the volume effect
Keep track of how many extra covers your promotions generate. Use the formula: Extra volume % = Discount % / (100% - Discount %) to check if you're breaking even.
✨ Pro tip
Run a 10-day test on any new promotion and measure daily volume increases. If you don't hit 80% of your break-even volume target by day 3, kill the promotion immediately.
Calculate this yourself?
In the KitchenNmbrs app you can do this in just a few clicks. 7 days free, no credit card.
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Frequently asked questions
Do I have to pay VAT on the discount amount?
No, you pay VAT on what the customer actually pays. The discount reduces your VAT base, so you owe less tax on the discounted portion.
How do I prevent promotions from eating into my profit?
Calculate in advance how much extra volume you need using the break-even formula. Monitor your food cost percentage weekly during promotion periods and stop immediately if volume targets aren't met.
Can I deduct discounts as business expenses?
No, discounts are revenue reductions, not expenses. They lower your taxable revenue but aren't deductible expenses on your tax return.
What percentage of my revenue should come from promotions?
Standard is maximum 10-15% of total revenue from discounts and promotions. More than that can structurally damage your profitability and create customer dependency on deals.
How do I calculate the impact of a 2+1 free promotion?
With 2+1 free you get 33% less revenue (€20 instead of €30), but your food cost increases from 30% to 45%. Volume needs to increase by 50% to break even.
Should I offer different discount percentages for high-margin vs low-margin items?
Absolutely. High-margin items like beverages can handle 20-30% discounts better than low-margin entrees. Calculate break-even volume for each category separately before launching promotions.
📚 Sources consulted
- EU Verordening 852/2004 — Levensmiddelenhygiëne (2004) — Official source
- EU Verordening 853/2004 — Hygiënevoorschriften voor levensmiddelen van dierlijke oorsprong (2004) — Official source
- EU Verordening 1169/2011 — Voedselinformatie aan consumenten (2011) — Official source
- NVWA — Hygiënecode voor de horeca (2024) — Official source
- NVWA — Allergenen in voedsel (2024) — Official source
- Codex Alimentarius — International Food Standards (2024) — Official source
- FSA — Safer food, better business (HACCP) (2024) — Official source
- BVL — Lebensmittelhygiene (HACCP) (2024) — Official source
- Warenwetbesluit Bereiding en behandeling van levensmiddelen (2024) — Official source
- WHO — Foodborne diseases estimates (2024) — Official source
Food Standards Agency (FSA) — https://www.food.gov.uk
The HACCP standards shown in this application are for informational purposes only. KitchenNmbrs does not guarantee that displayed values are current or complete. Always consult the FSA or your local authority for the latest regulations.
Written by
Jeffrey Smit
Founder & CEO of KitchenNmbrs
Jeffrey Smit built KitchenNmbrs from 8 years of hands-on experience as kitchen manager at 1NUL8 Group in Rotterdam. His mission: give every restaurant owner control over food cost.
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