Translation guide
The English phrase 'top up' has several distinct uses. This guide covers the most common meanings for learners: adding money to a prepaid balance, refilling a drink, and adding liquid to a container. It also notes the British English meaning of refueling a vehicle.
To add money to a prepaid card, mobile phone, or digital wallet.
The most common and natural way to say 'top up' for prepaid cards, mobile phones, and electronic money. It is a loanword from English 'charge'.
Suicaに1000円チャージした。
I topped up my Suica with 1,000 yen.
My phone balance is low, so I need to top it up.
Literally 'deposit money'. Used for adding funds to an account, but sounds more formal or banking-related. For prepaid cards, チャージする is more common.
口座に1万円入金しました。
I deposited 10,000 yen into my account.
Means 'replenish' or 'refill'. Can be used for topping up a balance, but it's less common and more formal. Usually used for physical supplies.
残高を補充する必要がある。
It is necessary to top up the balance.
To add more of a beverage to a glass or cup, often in a restaurant or at home.
The standard way to ask for a refill in a restaurant. It literally means 'another serving' and is used for drinks and food.
コーヒーのおかわりをください。
Can I get a top up on my coffee?
おかわりはいかがですか？
Would you like a top up?
Means 'to pour more into'. Used when physically adding liquid to a glass or pot. Not typically used for ordering in a restaurant.
Similar to 注ぎ足す, but can also imply adding to a supply over time. Less common for simple refills.
To fill a partially full container with more liquid, such as a car's oil or a water tank.
The most common verb for topping up fluids like oil, coolant, or water in a container. It means 'replenish'.
エンジンオイルを補充した。
I topped up the engine oil.
バッテリー液を補充してください。
Please top up the battery fluid.
A casual, general verb meaning 'to add'. Can be used for topping up liquids in everyday conversation.
クーラントが減ってるから、足しておくね。
The coolant is low, so I'll top it up.
Can be used for adding liquid, but often implies adding to an existing batch, like soup stock. Less common for simple topping up.
To add fuel to a vehicle's tank. This is a British English usage; in American English, 'fill up' is more common.
The standard verb for refueling a vehicle. It literally means 'supply fuel'.
ガソリンを給油した。
I topped up the petrol.
Means 'to fill up the tank'. More specific than 'top up', implying filling to full. Often used at gas stations.
満タンにしてください。
Fill it up, please.
There is no single Japanese verb that covers all meanings of 'top up'. Always choose the expression based on what is being topped up: チャージする for electronic money, おかわり for drinks, 補充する for fluids.
チャージする is used for prepaid cards and mobile phones. 入金する is for bank accounts or formal deposits. Using 入金する for a Suica card sounds unnatural.
May I top up your tea?
Top up the sauce and simmer.
Top up the broth of the simmered dish.