Longfill E-Liquids Explained: Beat the UK Vape Tax & Save Money in 2026
With the new UK vape tax coming into force, the cost of ready-mixed e-liquids is set to rise significantly. For regular vapers, this could mean spending considerably more each month.
The good news? Longfill e-liquids offer a legal, cost-effective alternative that puts you back in control.
What Is a Longfill E-Liquid?
A longfill is a large bottle containing a small amount of highly concentrated flavour suspended in PG (propylene glycol). Unlike ready-mixed e-liquids, longfills cannot be vaped straight from the bottle, you need to dilute them first by adding:
- VG (vegetable glycerin)
- PG (propylene glycol)
- Nicotine shots
This DIY approach gives you complete control over your e-liquid's VG/PG ratio, nicotine strength, and final volume.
Why Longfills Avoid the Vape Tax
The UK vape tax applies to finished, ready-to-vape e-liquids only.
Longfills sidestep this because:
- They're not vapeable when sold
- The flavour is concentrated, not diluted
- You complete the mixing at home
The result: You pay less tax upfront and create more finished e-liquid for significantly less cost per ml.
Longfills vs Shortfills: What's the Difference?
| Shortfills | Longfills |
|---|---|
| Pre-diluted e-liquid, just add nic shot | Concentrated flavour—you mix everything |
| Fixed VG/PG ratio (usually 70/30) | Fully customizable ratios |
| Limited nicotine strength (typically 3mg max) | Create 3mg–20mg or higher |
| Ready in seconds | Takes 2–5 minutes to mix |
Bottom line: Shortfills are convenient; longfills are flexible and far more economical.
How to Mix a Longfill E-Liquid (Step-by-Step)
What you'll need:
- Your longfill bottle
- VG and PG base liquids
- Nicotine shots (18mg recommended for flexibility)
- Measuring cylinder or syringe
- Empty bottle (if needed)
Mixing steps:
- Remove the cap and nib from your longfill bottle
- Check the mixing guide on your longfill label
- Add VG and PG in the correct ratio
- Add nicotine shots to reach your desired strength
- Replace the cap and shake well for 30–60 seconds
- Let it steep (optional, some flavours improve after 24 hours)
Longfill Mixing Calculator: Real Examples
These examples use a 60ml longfill bottle containing 10ml of flavour concentrate (meaning you need to add 50ml of liquid to fill it).
We're using 18mg nicotine shots as they're the most common and give you the most flexibility.
Making 6mg Nicotine (50/50 VG/PG)
What to add:
- 20ml VG
- 10ml PG
- 2 x 10ml nicotine shots (18mg)
Total: 60ml at 6mg strength, 50/50 ratio
Making 12mg Nicotine (50/50 VG/PG)
What to add:
- 10ml VG
- 0ml PG (the flavour concentrate already contains PG)
- 4 x 10ml nicotine shots (18mg)
Total: 60ml at 12mg strength, 50/50 ratio
Note: At 12mg you're adding more nic shots, so less base liquid is needed.
Making 18mg Nicotine (50/50 VG/PG)
What to add:
- 5ml VG
- 0ml PG
- 5 x 10ml nicotine shots (18mg)
Total: 65ml at 18mg strength, approximately 50/50 ratio
Note: You'll need a larger bottle or decant some liquid, as this exceeds 60ml.
Making 20mg Nicotine (50/50 VG/PG)
What to add:
- 0ml VG
- 0ml PG
- 5 x 10ml nicotine shots (18mg)
Total: 60ml at exactly 20mg strength
Note: This is the maximum legal strength in the UK and uses nic shots only—no additional base needed.
Quick Reference: Nicotine Shot Guide
| Target Strength | 18mg Nic Shots Needed | VG to Add | PG to Add | Final Volume |
|---|---|---|---|---|
| 3mg | 1 shot | 25ml | 15ml | 60ml |
| 6mg | 2 shots | 20ml | 10ml | 60ml |
| 12mg | 4 shots | 10ml | 0ml | 60ml |
| 18mg | 5 shots | 5ml | 0ml | 65ml |
| 20mg | 5 shots | 0ml | 0ml | 60ml |
Based on 60ml longfill with 10ml flavour concentrate. Your longfill may vary—always check the label.
Top Tips for Mixing Success
Use a syringe or measuring cylinder – Accuracy matters, especially with nicotine shots
Shake thoroughly – 30–60 seconds minimum to ensure everything blends properly
Label your bottles – Write the strength and date mixed so you don't forget
Start lower if unsure – You can always add more nicotine, but you can't take it out
Check your longfill size – Some are 100ml or 120ml bottles, which changes the ratios
Keep spare bottles handy – For higher strengths (18mg+) you may need extra space
Why You Can't Vape Longfills Undiluted
Never vape a longfill straight from the bottle. The concentrate is far too strong and will:
- Taste extremely harsh
- Damage or clog your coils
- Potentially irritate your throat
Think of it like undiluted squash—it needs water to be drinkable.
Who Should Use Longfills?
Longfills are ideal if you:
- Vape regularly (especially MTL devices)
- Want to save money long-term
- Need higher nicotine strengths (12mg–20mg)
- Prefer custom VG/PG ratios (50/50, 60/40, 70/30)
- Don't mind spending a few minutes mixing
Stick with ready-mixed if you:
- Want grab-and-go convenience
- Vape infrequently
- Prefer not to handle nicotine or mixing supplies
Longfills: Pros & Cons
Pros:
- ✓ Significantly cheaper per ml after tax
- ✓ Full control over nicotine strength and ratio
- ✓ Create large volumes from one bottle
- ✓ Simpler than full DIY e-liquid mixing
Cons:
- ✗ Requires extra supplies (VG, PG, nic shots)
- ✗ Takes a few minutes to prepare
- ✗ Large bottles less portable than 10ml ready-mix
How Much Can You Actually Save?
For a regular vaper using 60ml per week:
- Ready-mixed e-liquid (post-tax): ~£15–£20/week = £60–£80/month
- Longfill e-liquid: ~£8–£12/week = £32–£48/month
Potential savings: £25–£30+ per month, or £300–£360 per year.
For MTL vapers and heavy users, the savings are even greater.
Ready to Make the Switch?
Longfills aren't complicated—once you've mixed your first bottle, the process becomes second nature. With vape taxes driving up costs across the UK, learning to mix longfills is one of the smartest moves you can make as a vaper in 2026.
Browse our longfill range and start saving today.