When the cup arrives

Both the NHS and the AAP put the first cup at around six months, at the same time as solid food. The NHS says to introduce your baby to drinking from a cup or beaker from around six months and offer sips of water with meals. The AAP recommends offering a cup when your child starts eating solid foods, usually around six months.

This is early enough that the cup is a curiosity rather than a replacement, which is the point. A baby who has been drinking from a cup for months when the bottle goes is in a very different position from one meeting a cup for the first time at thirteen months.

The valve is the argument

The single most consequential detail in this whole topic is whether the lid has a non-spill valve. The NHS is unambiguous: "a cup or beaker with a free-flow lid (without a non-spill valve) is better than a bottle or beaker with a teat as it will help your baby learn how to sip rather than suck".

A valved beaker requires sucking to draw liquid through. Mechanically, that is a bottle with a different shape. The developmental step you are trying to reach is sipping, which uses a different set of muscles and a different tongue movement. A non-spill lid keeps your floor clean at the cost of the thing you were doing it for.

The NHS accepts that an open cup will be messy at first and asks for patience: "be patient, your baby will gradually learn how to drink from an open cup". As soon as your child is ready, it recommends moving from a lidded beaker to an open cup.

The AAP is more permissive about the intermediate stage, allowing a training cup with a spouted lid or a cup and straw, and noting that some children go straight to an open cup without a straw and that this is fine too. It qualifies this by saying sippy cups "should be used only while little ones are learning", and that it is healthiest for children to drink from an open cup by about two years of age.

When the bottle should go

Here the two services differ by up to six months.

The NHS. "Once your baby is 1 year old, feeding from a bottle should be discouraged." That is a clean line at the first birthday.

The AAP. The transition should begin around six months when the first cup is offered, with the number of bottle feeds reduced slowly and the transition completed "sometime between 12 and 18 months".

Both are describing a gradual reduction rather than a single day of removal, and both put the start of the process at six months. The difference is only in where the deadline falls.

Why prolonged bottle feeding causes problems

The AAP sets out four consequences, and they are more concrete than the usual vague warnings.

Skipped meals. Children who sip from bottles during the day often do not feel hungry at mealtimes, so they get less of the fibre and nutrients in solid food. If you are constantly coaxing a toddler to eat, the AAP suggests bottles may be the cause.
Excess calories. Bottles become high-calorie supplements and snacks on top of meals.
Tooth decay. Early childhood caries, sometimes called baby bottle tooth decay, happens when teeth are constantly bathed in milk, formula or juice. The AAP also links prolonged bottle use to tooth alignment problems and notes that mouth muscles need strengthening for clear speech.
Increasing resistance. Toddlers cling to bottles more fiercely as time goes on, so starting earlier is easier for everyone.

The NHS makes the dental point from the other direction: comfort sucking from a bottle on sweetened drinks causes tooth decay, because drinks flow very slowly through a teat and the sugary substance stays in contact with the teeth for longer.

What goes in the cup

Water and milk, essentially. From around six months, once solids have started, you can offer sips of water from a cup or beaker with meals, and water for babies over six months does not need to be boiled first. Formula-fed babies under six months may need small sips of cooled boiled water in hot weather alongside their usual feeds; fully breastfed babies do not need water before solids start.

The rule about bottles and trainer cups is strict: nothing but breast milk, formula milk or water, and nothing added to the feed, including sugar, cereals, baby rice or chocolate powder. The AAP adds that when a child is using a sippy cup it should be filled only with plain fluoridated water, without juice or sugar.

The AAP's recommended drinks guidance for children under five follows the same shape: milk and water are the two drinks that belong, with juice limited and sugary drinks excluded.

Milk after the first birthday

Formula milks are not needed once your baby is twelve months old, and that includes first infant formula, follow-on formula, growing-up milks and toddler milks. Pasteurised whole cows' milk can become the main drink from twelve months. Skimmed and 1% milk should not be a main drink under five because they do not contain enough calories, though they can be used in cooking from one. Goats' and sheep's milk follow the same rules as cows' milk, and unpasteurised milk is not suitable for young children.

How to make the change

Drop one bottle at a time and replace it with a cup at the same point in the day, starting with the feed your child is least attached to, which is usually a daytime one. Offer the cup at meals where a bottle is not expected. Expect spills, and expect a period where less liquid goes in; that is normal while the skill is being learned. Keep the bedtime bottle for last if it is the hardest, and do not leave a child in bed with a bottle at any stage, since the NHS warns of choking as well as decay.

When to ask for advice

Speak to a health visitor, public health nurse or GP if your child is still exclusively bottle-fed well past their first birthday, if dropping bottles has caused milk intake to fall away sharply, if they cannot manage a cup at all by around eighteen months, or if you have concerns about their teeth. The AAP notes that a child with a chronic illness, physical differences or signs of small motor delay should have a schedule built around their abilities rather than the standard timeline.

Cups, Beakers and Dropping Bottles