top up

add more to something that is partly empty

B1

What does "top sth up" mean?

To top up something means to add more of it when the level has gone down, so that it is full or close to full again. The important idea is that the container or account already has some content — you are not starting from zero, just restoring or maintaining the level. For example, if your glass still has a little wine in it and someone pours in a bit more, they are topping it up. This phrasal verb is used for physical things like drinks, fuel, and car oil, but also for financial things like mobile phone credit, bank accounts, and pension savings. It is very common in everyday British and Irish English, and you will hear it often in both casual conversation and more practical, everyday situations.

Examples

How to use it

top up + object

The most common structure, used when the object is a noun phrase. The object follows the particle.

Could you top up the kettle before you put it on?

top + object + up

With short noun objects, separation is very natural and extremely common in everyday speech.

He topped his card up at the machine near the entrance.

top + pronoun + up

When the object is a pronoun, it must go between the verb and the particle — it cannot come after 'up'.

Your coffee looks a bit low — shall I top it up?

be topped up

The passive form is natural and commonly used, especially when talking about accounts, batteries, and tanks being refilled automatically or by someone else.

The prepaid card is topped up every month by direct debit.

top up (no object stated)

The object can be left out when it is obvious from the situation, especially when offering to refill someone's drink.

She walked around the table asking, 'Shall I top up?'

Common Collocations

top up a glasstop up your phonetop up an accounttop up the tanktop up a cardtop up your pension

Common Mistakes

Pronoun after the particle

When you use a pronoun as the object, it must go between 'top' and 'up', not after 'up'. Putting the pronoun after the particle is ungrammatical in English.

I need to top up it before we leave.
I need to top it up before we leave.
Confusing 'top up' with 'fill up'

'Top up' is used when something already has some content and you add a little more. 'Fill up' suggests starting from empty or near-empty and making something completely full. Use 'top up' when the glass, tank, or account already has something in it.

The tank was completely empty, so I topped it up.
The tank was completely empty, so I filled it up.

Usage

This phrasal verb is much more common in British and Irish English than in American English, where 'refill' (for drinks) or 'top off' (for fuel) are often used instead. It is neutral in register and works in both casual and more formal contexts.

Frequently Asked Questions

Is 'top up' British English? Do Americans say something different?

Yes, 'top up' is much more common in British and Irish English. American speakers often say 'refill' when talking about drinks, and 'top off' when talking about fuel. If you are learning British English, 'top up' is the natural choice across all these situations.

Can 'top up' be used for things that are not liquids?

Yes, and this is one of the most useful things about this phrasal verb. As well as drinks, fuel, and other liquids, you can top up a mobile phone (add credit), top up a bank account or prepaid card (add money), and even top up a pension or salary. All of these follow the same idea: adding more to something that is already partly there.

Is there a noun form of 'top up'?

Yes — 'top-up' is a very common noun in British English, usually written with a hyphen. You might see phrases like 'a top-up card', 'a top-up payment', or 'top-up loans'. The noun is used in both spoken and written English across everyday and financial contexts.

Can I use 'top up' in formal writing, for example in a letter about a pension or bank account?

Yes, 'top up' is neutral in register and is perfectly acceptable in more formal or professional contexts. You will often see it in financial documents, bank communications, and official letters, for example when talking about topping up a pension or a prepaid account.

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