Shortfills vs Nic Salt Bottles: Which E-Liquid Is Right for You?

Walk into any UK vape shop and the shelf splits in two. On one side, big 50ml to 200ml bottles with space at the top and a separate little bottle of nicotine to tip in. On the other, neat 10ml bottles that are ready to vape the second you unscrew the cap. Shortfills and nic salt bottles are the two ways Britain buys e-liquid, and choosing the wrong one means either paying double per ml or chain-vaping a strength that never quite satisfies.

This comparison settles it with real numbers: what each bottle actually is, the cost per ml before and after the UK vape duty, how nicotine strength really compares between a 3mg shortfill and a 20mg salt, which devices each format suits, and who should buy which.

The 30-second answer

Short on time? Here is the verdict up front, then the evidence below.

• Buy nic salt bottles if you use a pod kit or starter kit, want 10mg or 20mg nicotine, vape mouth-to-lung like a cigarette, or you are switching from smoking and need cravings handled fast.
• Buy shortfills if you use a sub-ohm tank, vape direct-to-lung at higher wattages, go through 5ml or more a day, or you want the lowest cost per ml.
• Buy both if you want cheap liquid at home and grab-and-go bottles for the commute. Plenty of vapers run this hybrid setup.
• After the vape duty, shortfills are still cheaper per ml, but the absolute price of a big bottle jumps hard. Light vapers barely notice; heavy vapers feel it.

Now, the full breakdown.

Meet the two contenders

Shortfills: the big bottle with homework

A shortfill is a larger-than-label bottle of 0mg e-liquid. You buy a “100ml shortfill” and the bottle actually holds 120ml, with the top 20ml left empty. That gap is for nicotine shots: small 10ml bottles of (usually) 18mg nicotine that you tip in and shake. Add two shots to a 100ml shortfill and you get 120ml of 3mg liquid.

Shortfills exist because of UK law. Nicotine-containing e-liquid cannot be sold in bottles bigger than 10ml, so the industry split the product in two: flavour and base in the big bottle, nicotine in the little ones. Most shortfills are 70/30 VG/PG for sub-ohm vaping, though 50/50 shortfills for pod kits exist too.

Nic salt bottles: the small bottle with the punch

A nic salt bottle is a ready-to-vape 10ml bottle, usually in 50/50 VG/PG, with nicotine salts pre-mixed at 5mg, 10mg or 20mg. Nicotine salts use a mild acid to smooth out the nicotine, so 20mg feels far less harsh than 20mg of old-style freebase nicotine would. That is why they became the default for ex-smokers: strong, smooth, fast satisfaction from a small pod device.

No mixing, no shaking, no maths. Open, fill, vape. The trade-off is volume: heavy vapers get through a lot of small bottles.

Round one: cost per ml, before the duty

This is where shortfills built their reputation. Bigger bottles cost less to make, bottle and ship per ml, and the 0mg base carries less regulatory cost than nicotine liquid. Here is how typical UK shelf prices work out.

The pattern is obvious: the bigger the bottle, the cheaper the ml. A 100ml shortfill lands at roughly a third of the per-ml price of a single 10ml nic salt. For a wider look at what vapers actually pay across formats, see our vape juice prices guide.

Put it in annual terms for a moderate 4ml-a-day vaper, which is about 1,460ml a year. At 20p per ml on nic salts, that is roughly £290 a year on liquid. At 10p per ml on 100ml shortfills, it is roughly £145. The shortfill saves around £145 a year for that vaper. Light vapers under 2ml a day barely feel the difference; heavy vapers over 6ml a day feel it a lot.

Round two: the duty changes the whole maths

From 1 October 2026, the UK Vaping Products Duty charges £2.20 per 10ml on e-liquid. That is 22p per ml, and it applies at every nicotine strength, including 0mg liquid. With 20% VAT charged on top, the real checkout hit is about 26.4p per ml. Pre-duty stock can still be sold while it lasts, with retailers able to clear old stock until 31 March 2027, so some shelves may hold old prices a while longer.

Here is what the duty does to the formats above, assuming the full charge is passed on.

Two things jump out. First, the percentage hit lands hardest on shortfills, because their pre-duty price was the lowest. A 100ml shortfill that cost £15 all-in can approach £43-48 once duty and VAT apply. Second, and this is the part most coverage misses, shortfills are still cheaper per ml after the duty. The duty is flat per ml, so the shortfill’s per-ml advantage survives untouched. What changes is the absolute bill.

We break the whole thing down, including what is and is not caught, in our UK vape tax explainer.

Round three: nicotine strength is not what it looks like

3mg versus 20mg looks like no contest, but the number on the bottle only makes sense next to the device it goes in.

Nic salts at 10mg or 20mg are designed for low-power mouth-to-lung vaping. A pod kit turns a small amount of liquid into vapour, so you need a high concentration for each puff to carry enough nicotine. The salt formulation keeps it smooth and delivers it fast, which is exactly what a recent ex-smoker needs when a craving hits.

Shortfills at 3mg are designed for sub-ohm direct-to-lung vaping. A sub-ohm tank at 40-60 watts vaporises far more liquid per puff, so even 3mg delivers a satisfying total amount of nicotine. Drop 20mg salts into that same tank and the result is unpleasant at best. The formats are tuned to their devices, not to each other.

A few practical notes on strength:

• You cannot get 20mg from a standard shortfill. The maths tops out around 3-6mg depending on bottle size and shots. If you need high strength, nic salts are the answer.
• Nic salt shots exist. Some vapers add 20mg nic salt shots to shortfills instead of freebase shots. The final mg is similar, but the vape feels smoother.
• Going down is easy, going up is not. Vapers who start on 20mg salts often step down to 10mg, then to 3mg shortfills as their device habits change. The reverse trip is rarer.

Round four: your device decides before your wallet does

This is the round that actually picks your winner, because the wrong liquid in the wrong device is a bad vape.

Sub-ohm tanks and DTL kits want high-VG liquid, usually 70/30. Thick liquid, big clouds, coils built for it. That is shortfill territory. Most shortfills are 70/30 for exactly this reason.

Pod kits and MTL starter kits want thin 50/50 liquid that wicks fast through small coils. That is nic salt territory. Put 70/30 in a small pod and you get dry hits and burnt coils.

The crossover: 50/50 shortfills exist for pod users who want big-bottle value without sub-ohm clouds. If you are still weighing vaping against smoking rather than choosing between bottles, our cigarettes vs vaping comparison lays out the evidence first.

Rule of thumb: match the liquid to the coil, not to the price tag. A cheap ml that burns your coil is not cheap.

Round five: flavour and choice

Both formats now cover the flavour map, but they got there by different routes.

Nic salt ranges exploded alongside the bar-salt trend, with disposable-style flavours bottled in 10ml form for refillable pods. If you loved a particular disposable flavour, there is a good chance it exists as a nic salt. Many of those flavours started life in disposables, and our best disposable vapes roundup shows where the trend came from.

Shortfill ranges lean broader and more traditional: desserts, tobaccos, bakeries and complex multi-note blends that suit longer sessions on bigger devices. A 120ml bottle commits you to one flavour for weeks, so shortfill ranges reward vapers who know what they like, while 10ml salts reward vapers who like to rotate.

Flavour quality itself is format-neutral. The same concentrate houses supply both, and a well-made salt tastes as good as a well-made shortfill. The difference is variety strategy: salts for sampling, shortfills for settling.

Round six: the faff factor

Honest scoring on convenience.

Nic salts win outright. Twist the cap, fill the pod, done. Ten seconds, no mess, no maths, no spare bottles rattling around your bag. For travel, work breaks and nights out, they are unbeatable.

Shortfills ask for a small ritual: pop the nib, squeeze in the shots, shake for 30 seconds, let it settle. It takes two minutes. Spillage is the real cost: nic shots are fiddly, and nicotine on your hands gets washed off immediately.

Verdict on faff: if the idea of mixing puts you off vaping entirely, that feeling is worth more than the per-ml saving. Start with salts. You can always switch later.

The rulebook: TPD in plain English

UK rules shape both bottles, and knowing them explains half the oddities on the shelf.

• Nicotine liquid is capped at 10ml per bottle and 20mg per ml. That single rule created both formats: 10ml salts live inside it, shortfills route around it by selling the nicotine separately.
• Nic shots are 10ml bottles, usually 18mg, and follow the same rules as any nicotine liquid: child-resistant caps, tamper seals, warning labels, ingredient lists.
• The 0mg shortfill base itself is not directly regulated as a tobacco product, but it still has to meet general product safety standards. Reputable brands label batch numbers and ingredients anyway.
• Tanks are capped at 2ml, which is why everyone refills so often regardless of bottle size. The bottle you buy and the tank you vape from live under different limits.

None of this is going away. If anything, the duty has made the rulebook more important, because every millilitre is now taxed.

The full head-to-head

Everything in one place.

The verdict: five vapers, five answers

The ex-smoker with a new pod kit: nic salts, 20mg to start. Smooth, strong, fast. This is the format that keeps people off cigarettes in the first month, and nothing else does that job as well.

The sub-ohm cloud vaper: shortfills, no contest. Your tank wants 70/30 at 3mg, your consumption wants bulk pricing, and salts would be wasted (and unpleasant) at your wattage.

The budget vaper: shortfills, even after the duty. The per-ml lead survives the tax because the tax is flat. Buy the biggest bottle of a flavour you trust and the maths stays in your favour.

The flavour butterfly: nic salts. Ten millilitres is a low-commitment way to try the new bar-style flavour everyone is talking about, and nobody wants 120ml of a flavour they are bored of by day three.

The hybrid vaper: both. Shortfills at home where the big bottle lives in a drawer, nic salts in the bag for work, travel and nights out. This is the setup a lot of experienced vapers quietly settle on, and it is the best answer for anyone who vapes in two different contexts.

Shortfills vs nic salts: quick answers

Can I use shortfills in a pod kit? Yes, if you pick a 50/50 shortfill. Standard 70/30 shortfills are too thick for most pod coils and will wick badly. Match the VG/PG to the coil first.

Can I get 20mg nicotine in a shortfill? No. The mixing maths caps standard shortfills around 3-6mg. If you need 10mg or 20mg, nic salt bottles are the format for it.

Do nic salts work in sub-ohm tanks? Technically yes, practically no. High-strength salts in a high-power tank deliver far too much nicotine per puff and the vape is harsh. Keep salts in low-power devices.

Which is cheaper after the vape duty? Shortfills, still. The duty adds the same 26.4p per ml to both, so the shortfill’s per-ml lead survives. But the price of a single big bottle jumps a lot, so the saving is spread across more millilitres.

Are shortfills legal in the UK? Yes. The 0mg base is a legal product and nic shots are regulated nicotine liquids. The format exists specifically to comply with the 10ml bottle limit.

Which lasts longer, a shortfill or a nic salt bottle? A mixed 100ml shortfill gives you 120ml, which is twelve 10ml bottles’ worth. For the same daily consumption, the shortfill lasts twelve times longer between purchases.

The bottom line

Shortfills win on price per ml and suit high-power vaping. Nic salts win on strength, simplicity and the switch from smoking. The duty made everything more expensive but did not change which format suits which vaper. Pick by your device and your nicotine needs first, let the cost maths confirm it second, and you will buy the right bottle the first time.