How to pack bottles and liquids so they do not leak in transit

A leaking bottle often does more harm than a broken one. The liquid soaks the box, the label can peel off, and the parcels packed next to it in the courier's bag can get spoiled too.

Small brands ship oils, sauces, shampoos and serums every day. In this lesson we go through the packing in order, one layer at a time, from the courier's rules to a simple test you can do at home tonight.

I will start with an honest limit. Packing cannot fix a cap that does not seal. Bubble wrap protects a bottle from knocks, but it does nothing for a closure that lets liquid through. Which bottle and cap suit your product is a question for your bottle supplier, who can test it with your actual liquid.

Step 1: Check the courier's rules before anything else

This step comes first because no packing will make a refused parcel acceptable.

I would rather you lose one day asking than have a parcel come back to you.

Couriers are particular about liquids, and the rules differ from one to the next. Let us look at what three of them publish.

1. Blue Dart's list of banned commodities (bluedart.com, October 2026) includes "Liquids & Semi-liquids", with a note that conditions apply and that specific items may be cleared under its security and operational norms. Its dangerous goods page says dangerous goods are not accepted on Blue Dart Express and Blue Dart Aviation services.
2. India Post's prohibited items page (last reviewed 12 August 2026) bars any explosive, inflammable, dangerous, noxious or deleterious substance.
3. DHL's Essential Packing Guide for Express Shipments (valid from 2026) warns that many common household liquids and powders are classified as dangerous goods and are carefully regulated for transport on aircraft.

For parcels going abroad, the Universal Postal Union's dangerous goods page (upu.int, October 2026) says perfumes can be flammable and are prohibited in international mail. It also names nail polish remover and aerosol cans.

Before your first liquid order, I suggest four things.

1. Tell your courier or shipping aggregator exactly what the product is. Ask whether they accept it, by surface or by air, and with what packing.
2. Get the answer in writing, by email or from your account manager.
3. If your product label carries a flammable warning, treat it as a dangerous good until the courier tells you otherwise.
4. Declare the contents honestly when you book. A liquid hidden in the description turns a small leak into a big dispute.

Step 2: Prepare the bottle

We now prepare the bottle itself.

1. Choose a bottle with a screw cap that closes well. If your product allows it, a bottle with an inner seal under the cap gives an extra barrier. Your bottle supplier can tell you what is available.
2. Leave a little air space at the top. Do not fill to the brim. Liquid expands when the temperature rises, and a parcel can spend hours in a hot vehicle, especially in an Indian summer.
3. For glass bottles, plan for more cushioning. Glass breaks, while plastic usually only dents or squeezes.
4. For pumps and sprays, use the lock if the pump has one. If it does not, tape the pump head down. For a long or rough route, you can also ship the bottle with a plain screw cap and put the pump in the box separately.

Step 3: Seal the cap

We now close the most common leak point, the joint between the cap and the neck.

1. Tighten the cap firmly by hand.
2. Wrap tape around the joint where the cap meets the neck, two or three turns. I like tape for this because every packing table already has it. Wrap it in the same direction that the cap tightens. Then, if the tape is pulled, it pulls the cap tighter and not looser.
3. As an alternative, use a shrink band. This is a plastic sleeve that is shrunk tight over the cap and neck with heat. It holds the cap and also shows the customer that the bottle has not been opened.

For droppers and thin liquids, some packers also put a small square of plastic film over the bottle mouth before screwing the cap on. It is a cheap extra layer.

Step 4: Bag each bottle with something absorbent

Now we bag each bottle. Please do not skip this layer.

1. Put each bottle in its own leak-proof plastic bag, such as a zip-lock bag.
2. Put absorbent material inside the bag with the bottle: tissue, paper towel or an absorbent pad. I suggest using enough to soak up the whole contents of the bottle if it leaks fully.
3. Press out the extra air and seal the bag.

The UPS Packaging Guidelines (November 2024) say to seal bottles and containers and place them in plastic or spill-proof bags. DHL's guide asks for liquids to be sealed in a plastic bag before they go into a strong double-wall box, and it says single packaging is not allowed.

Now we have two layers, the bottle and the bag.

If one fails, the other still holds the liquid.

Step 5: Box it upright, with cushioning all round

We use a box for every liquid order, with no exceptions.

1. Use a strong corrugated box, not a mailer bag. DHL asks for a double-wall box for liquids. For glass bottles, I would use double wall even for domestic parcels.
2. Stand each bottle upright.
3. Keep bottles apart. Wrap each one, or use cardboard dividers, so no bottle touches another bottle or a wall of the box.
4. Cushion the bottom and the top, and fill every gap so nothing can move. Our lesson on how to pack a parcel covers these steps in detail.
5. Mark the box with "This side up" arrows on at least two sides.
6. Seal the box with the H-taping method from our lesson on how to tape a shipping box.

There is a hard truth about those arrows. DHL's guide says its teams look for handling labels, but it cannot guarantee that a box stays the right way up. So we pack as if the parcel will travel on its side, or upside down. The taped cap and the sealed bag are what protect you then.

Step 6: Test before your first shipment

Our last step is a test, done before you sell a new liquid in volume.

This test costs you one bottle of product and one night. I do not know a cheaper check.

1. Fill a bottle exactly as you would for a customer. Cap it, tape it, and bag it if you like.
2. Lay it upside down on a dry paper towel and leave it overnight.
3. In the morning, look for any wet spot or stain on the paper. Oils leave a mark that is easy to see.
4. For a plastic bottle, squeeze it gently and watch the cap and the shoulder of the bottle.
5. Repeat the test with a bottle that has been kept in a warm place for a few hours.

If the paper stays dry, ship one packed box to a friend in another city before you sell at volume.

Oils, sauces and cosmetics: small differences

Oils tend to creep along the threads of a loose cap, so for oils the tape around the cap matters most. I would tape every oil bottle, without exception. Do the overnight test with every new bottle or cap you start using.

Sauces and pickles often come in glass jars, which are heavy. Give them thicker cushioning and a double-wall box, and keep each jar in its own bag.

Cosmetics bring pumps, droppers and sprays. Lock them, tape them, or swap them for a screw cap for the trip. Small glass dropper bottles also need the cap taped, because a dropper cap can work loose with vibration.

Mistakes to avoid

We have covered each of these above. Here they are in one list for your packing table.

1. Booking a liquid without asking the courier first.
2. Filling the bottle to the very top.
3. Relying on "This side up" arrows alone.
4. Shipping liquids in a mailer bag.
5. Putting two bottles in one bag, where they knock against each other.
6. Packing a liquid next to books or clothes in the same order without a sealed bag around the bottle.

If you are not sure whether your product can travel at all, start with the courier question in Step 1. Then tell us about the product through our contact page, and we will help you think through the packing around it.