A shortfill is a bottle of e-liquid that's been deliberately underfilled, sold with no nicotine in it, so you can add your own nicotine strength before you vape it. A 100ml bottle usually holds around 70ml or 80ml of liquid, leaving room to drop in one or two 10ml nic shots and shake it up. It's a format built entirely around a piece of UK law: nicotine-containing e-liquid can only be sold in 10ml bottles, but nicotine-free liquid has no such cap. Shortfills exist because of that gap, and they've become one of the cheapest, most flexible ways to buy vape juice in bulk.
If you're moving from prefilled pods to a refillable setup, or you just get through a lot of e-liquid and are tired of buying 10ml bottles one at a time, shortfills are worth understanding properly. They're not complicated once you've done it once, but the mixing step trips people up, and the legal side (why they're sold without nicotine at all) confuses plenty of vapers who've never had it explained. This guide covers what a shortfill actually is, how the nic shot system works, which ratios suit which devices, and what changes for shortfill buyers when the UK's new Vaping Products Duty lands on 1 October 2026.
What Is a Shortfill E-Liquid?
A shortfill is simply a large bottle, typically 50ml, 100ml or occasionally 120ml, that isn't filled to the top. A 100ml shortfill bottle might contain 70ml or 80ml of e-liquid, leaving 20ml to 30ml of empty space. That gap is intentional. It's there so you can pour in one or more 10ml nicotine shots, cap the bottle, shake it, and end up with a full 100ml of nicotine e-liquid at the strength you chose.
Vape Desires stocks a wide range of shortfills across the e-liquids collection, including 100ml bottles from Fantasi, Doozy, TENTEN, Pod Salt Nexus, Kingston AU, Drifter Bar Juice, The Custard Company, Big Fruit and others. Every one of them ships as sold, that is, 0mg nicotine, ready for you to add a shot if you want one.
Shortfill bottles usually come with a childproof cap and a nozzle tip designed to control the pour when you're adding a nic shot or filling a tank. Some brands use a simple screw cap instead, in which case you'll need a separate dripper tip or funnel to fill a tank cleanly without spilling. Neither format is better than the other functionally, it's mostly down to brand preference, but it's worth checking the cap type before buying if you're planning to refill a tank directly from the bottle rather than decanting into smaller containers first.
The shortfill format only exists because of a specific quirk in how UK nicotine law is written. Once you understand that quirk, the rest of the format makes sense.
Why Shortfill Bottles Are Sold Without Nicotine
Under the Tobacco and Related Products Regulations 2016 (TRPR), which implement the EU's Tobacco Products Directive into UK law, any e-liquid containing nicotine has to be sold in a "dedicated refill container" of no more than 10 millilitres. That's regulation 36(2) of the TRPR, and it's the reason every nic salt and freebase e-liquid bottle in the UK tops out at 10ml, whatever the brand.
Nicotine-free e-liquid isn't covered by that 10ml cap at all. The limit exists to control how much nicotine a single retail container can hold, so once nicotine is removed from the equation, there's nothing in TRPR stopping a manufacturer selling liquid in 50ml, 100ml or larger bottles. That's the entire basis for the shortfill format: bottle the base liquid (PG, VG, flavourings, no nicotine) in a large size, then sell the nicotine separately in TRPR-compliant 10ml shots that the customer combines themselves.
It's a legal workaround built on a genuinely different mechanism to the 2ml pod and 10ml bottle system used by prefilled pod kits and nic salts. If you want the full picture on how that 2ml/10ml pairing works for prefilled devices, the 2ml + 10ml vape system guide covers it separately, since shortfills solve a different problem in a different way.
How the 10ml Nic Shot Rule Works With Shortfills
A nic shot is a 10ml bottle of nicotine, sold on its own, TRPR-compliant because it's a dedicated refill container under 10ml. UK nic shots are almost always 18mg/ml, the standard strength manufacturers settled on because the maths works cleanly: add one 18mg shot to 100ml of 0mg liquid and you land close to 2mg/ml, a strength plenty of long-term vapers on lower nicotine find comfortable.
Vape Desires sells nic shots separately from the shortfill bottles themselves. The Nic Nic 10ml nicotine shot, 18mg, 100% VG is a freebase shot built for mixing into standard shortfills, while the Nic Nic flavourless 50VG nicotine salt shot is a nic salt version for anyone who wants a smoother throat hit at the same strength. Whichever you use, the shot itself is nicotine only, no flavour, so it won't dilute or change the taste of the shortfill it's mixed into beyond adjusting the overall PG/VG ratio slightly.
The maths is simple once you've seen it laid out. A 100ml shortfill bottle filled to 70ml, with one 18mg shot added, gives you 80ml of liquid at roughly 2.25mg/ml. Add two shots to a 100ml bottle filled to 80ml and you get 100ml at around 3.6mg/ml. Bottles are usually pre-measured by the manufacturer so the headspace matches a clean result once you've added the "correct" number of shots for that product, and the label will tell you how many shots the bottle is designed for.
Shortfill Ratios: What 50/50 and 70/30 Actually Mean
Every shortfill lists a VG/PG ratio, most commonly 50/50 or 70/30. That number tells you the split between vegetable glycerine (VG) and propylene glycol (PG) in the base liquid, and it matters more than most new shortfill buyers expect.
VG is thicker and produces bigger vapour clouds. PG carries flavour more sharply and gives a firmer throat hit, and it's thinner, so it flows more easily through narrow airflow. A 50/50 shortfill behaves closer to a standard nic salt or prefilled pod liquid: tight draw, noticeable throat hit, good flavour clarity, well suited to mouth-to-lung devices and pod kits with narrow airflow. A 70/30 shortfill leans VG-heavy, producing softer throat hit and thicker vapour, better matched to devices with wider airflow and lower resistance coils.
The Doozy Infinity Pod Fill 100ml shortfill (50/50) is built specifically for pod kits and MTL devices, where the tighter ratio suits narrow airflow. The Doozy Infinity 100ml shortfill (70/30) suits looser, higher-airflow setups. Picking the wrong ratio for your device won't damage anything, but it can mean a weaker flavour hit or a liquid that feels too thin or too thick for the coil it's going into.
Shortfill Nicotine Strength Options After Mixing
Because shortfill strength depends on how many shots go into how much headspace, the final nicotine level isn't fixed the way a 10ml nic salt bottle is. It's worth knowing roughly what common combinations produce before you mix anything.
One 18mg shot added to 90ml of shortfill liquid (topping up to 100ml) gives approximately 1.8mg/ml, a low strength suited to vapers who've already cut down significantly or who vape very frequently throughout the day. One shot into 80ml, topped to 100ml, lands around 2.25mg/ml, a common middle-ground strength. Two shots into an 80ml fill, making 100ml, gives roughly 3.6mg/ml, the upper end of what most shortfill combinations reach without adding a third shot. Going beyond two shots per 100ml starts pushing into freebase strengths that many vapers find harsh through anything other than a sub-ohm tank built for high-VG, high-wattage use.
If you want a strength closer to the 20mg/ml salts used in most prefilled pod kits, a shortfill mixed with freebase shots generally can't get there cleanly within a 100ml bottle using standard 18mg shots, since you'd need five or more shots to reach that concentration, leaving very little room for base liquid. That's a genuine limitation of the format rather than a flaw in how you're mixing it, and it's the main reason shortfills suit lower-strength, higher-volume vaping rather than the high-strength, low-volume pattern typical of sealed pod systems.
PG Sensitivity and Choosing a Shortfill Ratio
A small number of vapers find propylene glycol irritating, typically experiencing a dry or sore throat, mild cough, or a scratchy sensation that doesn't ease off with normal use. If that sounds familiar, a higher-VG shortfill, 70/30 or above where available, usually reduces the irritation noticeably, since VG carries less of the throat-drying effect that PG produces at higher concentrations. Genuine PG sensitivity is uncommon but not rare, and switching ratio is the first thing worth trying before assuming a device or coil is at fault.
The trade-off is throat hit and flavour sharpness. Vapers who specifically like a firm throat hit similar to smoking often find high-VG liquid feels flat or muted by comparison, even at the same nicotine strength, because PG is doing a lot of that sensory work in a standard 50/50 blend. There's no universally "correct" ratio here, it genuinely comes down to personal tolerance and preference, and trying a smaller bottle before committing to a full 100ml is a reasonable way to test a new ratio without much risk.
Shortfills vs Nic Salts: Which Suits a Prefilled Pod Kit
Most prefilled pod kits sold in the UK, disposables-format reusable devices included, come pre-loaded with nic salt e-liquid, not shortfill-based freebase. There's a practical reason for that: nic salts hit a smoother throat sensation at higher strengths (up to the UK's 20mg/ml legal cap), which suits the tight, low-power draw of a sealed pod system. Freebase liquid at the same strength feels notably harsher through the same coil.
Shortfills mixed with freebase nic shots generally land in the 2mg/ml to 6mg/ml range once diluted, well below the 20mg/ml salt strength most disposables-replacement pod users are used to. That makes shortfills a poor direct swap for someone who's used to a 20mg salt pod and wants the same nicotine delivery. They're a better fit for vapers who already prefer lower strengths, who are refilling an open pod or tank system rather than using sealed prefilled pods, or who want a big bottle of liquid without paying per-10ml nic salt prices.
If you're deciding between the two formats for your own setup, the nic salts vs freebase nicotine guide and the nicotine strength guide both go into more depth on strength and format choice than makes sense to repeat here.
Are Shortfills Legal in the UK?
Shortfills are a fully legal, TRPR-compliant format, provided every part of the system stays within the rules that apply to it. The base shortfill bottle is legal because it contains no nicotine and therefore isn't covered by the 10ml cap in regulation 36(2). The nic shot is legal because it's sold separately in a container under 10ml, at or below the 20mg/ml UK nicotine strength limit. Neither product breaches TRPR on its own, and combining them at home isn't restricted either, since the law regulates how nicotine liquid is sold, not how a consumer mixes liquid they already legally own.
This is a different legal mechanism to the ban on single-use disposable vapes, which took effect on 1 June 2025 under the Environmental Protection (Single-use Vapes) (England) Regulations 2025, with equivalent rules across Scotland, Wales and Northern Ireland. That ban targets non-rechargeable, non-refillable devices. Shortfills, nic shots and the refillable devices they're used in are reusable products and sit outside that ban entirely. Reusable vape products remain legal in the UK; it's single-use disposables that were banned.
Manufacturers selling nicotine products in the UK, including nic shots, are required to notify them to the MHRA before sale under the same TRPR framework. The 0mg shortfill base liquid itself doesn't carry nicotine, so it falls outside MHRA notification requirements in the way a nic shot or nic salt does; if you want to check a specific nic shot's notification status, that's worth confirming directly with the supplier or MHRA's public records rather than assuming from the bottle alone.
Shortfill Bottle Sizes: 50ml, 100ml and 120ml Compared
Most shortfills on the market come in 50ml or 100ml bottles, with 120ml occasionally used by specific brands. The size you pick is really a question of how many nic shots you want to add and how much liquid you get through.
A 50ml shortfill typically takes one 10ml shot to reach a full 60ml at a workable strength, or is sold pre-shorted to take a shot and land at exactly 50ml or 60ml depending on the brand's fill level. A 100ml shortfill usually takes one or two shots. Buying 100ml bottles works out cheaper per millilitre than 50ml in almost every case, since you're paying once for the bottle, cap, and packaging rather than twice. If you vape through liquid quickly and stick to one or two flavours, 100ml shortfills are the more economical choice; if you like rotating flavours often, smaller bottles mean less risk of a flavour going stale before you finish it.
Vaping Products Duty and Shortfill E-Liquids From October 2026
The UK's new Vaping Products Duty takes effect on 1 October 2026, with business registration having opened on 1 April 2026. The duty is a flat rate of £2.20 per 10ml of vaping liquid, applied regardless of nicotine strength, and is intended to simplify calculation and reporting for HMRC and vape businesses alike rather than scaling with nicotine content.
For shortfill buyers, the practical effect is that the base liquid volume in a shortfill bottle is likely to be dutied on the same per-10ml basis as any other vaping liquid, since the duty applies broadly to vaping liquid intended to be vapourised, not solely to liquid already containing nicotine at point of sale. Exactly how the duty is calculated and charged for a shortfill's 0mg base liquid versus its accompanying nic shot is a detail worth confirming directly with HMRC guidance or your supplier nearer the October 2026 start date, since the practical retail price impact will depend on how registered producers pass the duty through. Expect shortfill and nic shot prices generally to shift from October 2026 as the duty beds in.
Shortfill Shelf Life and Storage
E-liquid doesn't spoil the way food does, but it does degrade. Nicotine oxidises over time, especially with heat and light exposure, and flavourings can fade or shift in taste as VG and PG interact with the flavour compounds over months. An unopened shortfill kept in a cool, dark cupboard should hold its flavour and (once nicotine is added) its strength reasonably well for a year or more; once opened and mixed with a nic shot, it's sensible to use it within three to six months for the best flavour, sooner if it's stored somewhere warm.
Direct sunlight and heat are the two things that degrade a shortfill fastest, so a windowsill or a car glovebox in summer are both poor storage choices. A cupboard, drawer, or anywhere consistently cool and dark works better. Once mixed with a nic shot, always label the bottle with the date and the strength, since an unlabelled mixed shortfill is easy to lose track of, and there's no visual way to tell how much nicotine is in a bottle just by looking at it.
Common Shortfill Mistakes to Avoid
The most common shortfill mistake is adding too many nic shots, either because the headspace wasn't measured correctly or because someone assumes more shots means a stronger hit without checking the maths. Overfilling can also mean liquid spills out of the bottle when you shake it, or that there's no room left for the shot at all. Check the bottle's fill line and the shot count the label recommends before adding anything.
The second common mistake is mismatching VG/PG ratio to the device. Putting a heavily VG-weighted 70/30 shortfill through a tight MTL pod coil rated for thinner liquid can lead to weak flavour, gurgling, or a coil that struggles to wick fast enough, producing a burnt taste. Matching ratio to device, 50/50 for MTL pod kits, 70/30 for looser airflow setups, avoids most of this. If you're getting a burnt taste regardless of ratio, that's usually a wicking or coil-age issue rather than a shortfill problem specifically; the burnt taste troubleshooting guide covers the usual causes.
The third mistake is not shaking the bottle properly after adding a nic shot. Nicotine and flavour compounds need a genuine shake, thirty seconds to a minute, not a couple of quick swirls, to distribute evenly through the liquid. An under-mixed shortfill can deliver an inconsistent hit from the first fill to the last, stronger at the top, weaker at the bottom, simply because the nicotine hasn't spread through the bottle.
A fourth mistake worth flagging is buying a shortfill and a nic shot from mismatched brands without checking the base liquid's PG/VG ratio against the shot's. Most nic shots are either 50/50 or close to 100% VG, and adding a heavily VG shot to an already VG-heavy 70/30 shortfill can push the final mix thicker than the device it's meant for can handle comfortably. Checking both labels before buying, rather than after mixing, avoids wasting a bottle.
Choosing the Right Shortfill Flavour
Shortfill flavour ranges tend to be broader and more experimental than 10ml nic salt lines, partly because the format has historically been popular with sub-ohm and cloud-focused vapers who want variety over convenience. Fruit blends, dessert and bakery flavours, menthol and ice variants, and drink-inspired liquids are all well represented across brands like Fantasi, TENTEN, Pod Salt Nexus, Kingston AU, Drifter Bar Juice, Big Fruit and The Custard Company, all stocked in the shortfill range at Vape Desires.
If you already know which nic salt or pod flavour you enjoy, checking whether the same brand does a shortfill version is a reasonable starting point, since flavour profiles usually carry across a brand's range. If you're picking blind, dessert and bakery shortfills (custard, cake, biscuit-style profiles) tend to suit all-day vaping better than sharp fruit or menthol, which some vapers find fatiguing over a full bottle; that's a general pattern rather than a fixed rule, and taste is genuinely personal.
Frequently Asked Questions About Shortfill E-Liquids
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Is a shortfill e-liquid legal in the UK?
Yes. A shortfill bottle sold with 0mg nicotine falls outside the TRPR 10ml container limit that applies specifically to nicotine-containing liquid, so it can legally be sold in larger sizes like 50ml or 100ml. Adding a TRPR-compliant nic shot afterwards is legal too, since the law governs how nicotine liquid is sold, not how you combine liquid you've already bought.
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Do I have to add a nic shot to a shortfill?
No. If you want a nicotine-free vape, you can use a shortfill exactly as it comes, with no shot added. Shortfills are popular with vapers who've reduced their nicotine intake to zero but still want to vape flavoured liquid without the habit of nicotine itself.
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How many nic shots does a 100ml shortfill need?
That depends on the bottle's fill level and the strength you want. A 100ml bottle filled to 80ml with one 18mg shot lands around 2mg/ml once topped up to 100ml. The same bottle with two shots (needing 20ml of headspace) lands around 3.6mg/ml. Check the specific bottle's label, since fill levels vary between brands and aren't always identical.
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Can I use a shortfill in a prefilled pod kit?
No, not directly. Prefilled pod kits use sealed, factory-filled pods that aren't designed to be refilled or opened. Shortfills are for refillable, open-system devices like pod tanks or sub-ohm kits. If you're using a genuinely refillable device, such as the Aspire Gotek Nano pod kit or the Vaporesso Armour Ultra mod kit, a shortfill mixed to the right strength works well; a sealed prefilled pod device doesn't take shortfill liquid at all.
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What VG/PG ratio should I choose for a shortfill?
50/50 suits mouth-to-lung devices and tighter airflow, giving a throat hit and flavour clarity closer to a standard nic salt. 70/30 suits looser, higher-airflow devices and produces thicker vapour with a softer throat hit. Check your device's recommended liquid type before choosing.
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Does a shortfill go off if I don't use it quickly?
E-liquid degrades gradually rather than spoiling outright. Flavour can fade and nicotine can weaken slightly over time, faster with heat and light exposure. An unopened shortfill stored cool and dark should keep reasonably well for a year or more; once mixed with a nic shot, using it within three to six months is a sensible guideline for the best flavour and consistent strength.
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Is a shortfill cheaper than buying 10ml nic salt bottles?
Generally, yes, per millilitre. A 100ml shortfill plus one or two 10ml nic shots usually costs less overall than the equivalent 100ml to 120ml of nic salt bought in 10ml bottles, since you're only paying full packaging costs once rather than ten times over. Exact pricing varies by brand and should be checked against current listings rather than assumed.
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What's the difference between a shortfill and a nic salt bottle?
A nic salt bottle is sold at 10ml, already contains nicotine (usually up to the UK's 20mg/ml legal maximum), and is ready to use straight away. A shortfill bottle is larger, usually 50ml or 100ml, sold with no nicotine at all, and needs a separate nic shot added if you want a nicotine hit. Nic salts suit prefilled pod kits and low-volume, high-strength vaping; shortfills suit refillable tanks and higher-volume, lower-strength vaping.
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Can I mix two different shortfill flavours together?
You can, and some vapers do it deliberately to create a custom blend, but it's not something manufacturers test or guarantee will taste good. Mixing flavours changes the overall PG/VG ratio slightly depending on each bottle's base, and there's no way to predict how two flavour profiles will combine until you try it. If you want to experiment, doing it in a small batch first avoids wasting a full 100ml bottle on a combination that doesn't work.
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Will the new Vaping Products Duty make shortfills more expensive?
Likely, yes, from 1 October 2026. The duty is charged at a flat £2.20 per 10ml of vaping liquid regardless of nicotine strength, and applies broadly to vaping liquid intended for use in a vape. Exactly how that duty is passed through to shortfill and nic shot pricing will vary by supplier, and the practical price change is worth checking closer to the October 2026 start date.
Shortfill Compliance and Safety
Shortfill e-liquids and nic shots are for adult smokers and vapers aged 18 and over only. Sale of nicotine-containing e-liquid to anyone under 18 is illegal in the UK, and this content is not written for, or intended to appeal to, anyone under that age.
Nic shots contain nicotine, an addictive substance. Nicotine-free shortfill base liquid does not, but once a nic shot is added, the resulting mixture should be treated and stored with the same care as any nicotine-containing e-liquid: kept away from children and pets, stored upright, and never left within reach of anyone who might mistake it for a drink or flavoured syrup.
The shortfill and nic shot format is designed for legal UK sale under the TRPR framework covering refill containers (10ml maximum for nicotine-containing liquid) and refillable tank capacity (2ml maximum). Nic shots sold as standalone nicotine products should carry MHRA notification; if you want to check a specific product's notification status, MHRA's public records or the supplier are the right place to confirm it rather than assuming from packaging alone. Reusable vape products, including the refillable devices shortfills are designed for, remain legal in the UK; single-use disposable vapes were banned from 1 June 2025 under the Environmental Protection (Single-use Vapes) (England) Regulations 2025 and equivalent rules across the rest of the UK. This is general product information, not medical advice, and nothing here should be read as a claim that vaping is a guaranteed route to quitting smoking.
