Vape tank sizes and the UK 2ml rule: what the law says and why it matters

The limits come from the Tobacco and Related Products Regulations 2016, the UK law that put the EU Tobacco Products Directive into effect. They apply to anything sold in the UK that holds or contains nicotine liquid.

Tanks and pods may hold no more than 2ml. Refill bottles containing nicotine may hold no more than 10ml. Nicotine strength is capped at 20mg/ml. Products must also be notified to the MHRA before they can be sold.

These rules shape almost every vape you see on a UK shelf, from the smallest pod to the biggest sub-ohm tank.

The limits are not new. They came in nearly a decade ago and have been part of UK vaping ever since. The timeline shows the key dates for the rules that affect your tank and liquid.

Since then, the rules have been kept in UK law after Brexit, and further changes have arrived around disposables. Single-use vapes were banned in the UK from 1 June 2025, which pushed many vapers towards refillable pod kits and tanks.

None of this stops you choosing the setup you enjoy; it just shapes the hardware. For how and when your order arrives, see our delivery page.

A 2ml tank lasts a long time on an MTL setup and empties surprisingly fast on a sub-ohm one. How often you refill depends almost entirely on your coil resistance and power.

The easiest way to cope is to carry liquid with you. A 10ml bottle is pocket-sized and refills a 2ml tank about five times. Sub-ohm vapers often carry a small bottle decanted from a shortfill.

Refill before the tank gets low. Letting the level drop below the coil's wicking holes invites dry hits, so topping up at around a third full keeps the coil happy. Our guide to filling a tank without flooding covers the technique.

The 10ml limit only applies to liquid that contains nicotine. That is why shortfills exist: they are nicotine-free liquid in a larger bottle, typically 50ml in a 60ml bottle, leaving space to add a nicotine shot.

A nicotine shot is a 10ml bottle of unflavoured nicotine, usually 18 or 20mg. Add one 18mg shot to a 50ml shortfill and you get 60ml at around 3mg; two shots in a 100ml shortfill give 120ml at the same strength. Nicotine is addictive, so be sure the strength you mix is the one you want.

The split shows what a typical mix looks like.

Capacity is fixed at 2ml, but tanks vary a lot in width. That matters when you pair a tank with a mod. A tank wider than the top of the mod overhangs the edge, which some vapers dislike for looks and which can make the mod harder to stand up.

MTL tanks are usually slim, around 18 to 22mm. Sub-ohm tanks are generally 24 to 27mm. The bars show widths for some of the tanks in our tank range.

Before buying, compare the tank diameter with the width of your mod's top plate. A few millimetres of overhang is common, but a large one looks and feels awkward.

The 2ml limit is one of the most noticeable UK vaping rules, but it does not need to be a hassle. Choose a setup that matches your vaping, carry a bottle if you sub-ohm, and refill before the tank runs low.

If you need a replacement glass, make sure it is the 2ml version made for your tank. Our spare glass section lists them by model.

Remember too that the limits apply per container. Carrying two pods or a couple of 10ml bottles is perfectly normal and is how most heavy vapers handle a busy day. One question to finish.