Tôi thanh toán lệ phí.

In this sentence, thanh toán functions as a single verb expression meaning to make a payment / to settle a payment.

Vietnamese has many verbs that are written as two separate words but behave like one unit in meaning. So here you should learn thanh toán as a set phrase.

• thanh toán tiền = pay money / settle a payment
• thanh toán hóa đơn = pay a bill
• thanh toán lệ phí = pay a fee

So even though it is written as two words, it works like one verb phrase.

Thanh toán is correct, but it sounds somewhat formal and administrative.

Depending on the situation, Vietnamese speakers might also say:

• Tôi trả lệ phí. = I pay the fee.
• Tôi đóng lệ phí. = I pay the fee.
• Tôi thanh toán lệ phí. = I make payment of the fee.

Nuance:

• thanh toán: formal, often used in offices, banking, invoices, official transactions
• trả: very common everyday word for paying
• đóng: very common for fees, tuition, insurance, taxes, membership dues, etc.

So your sentence is natural, especially in an official or written context.

Phí is the general word for fee / charge.

Lệ phí is more specific and more formal. It is often used for official, administrative, or government-related fees.

For example:

• phí gửi xe = parking fee
• phí dịch vụ = service charge
• lệ phí visa = visa fee
• lệ phí đăng ký = registration fee

So lệ phí usually sounds more official than plain phí.

Vietnamese does not use articles the way English does. There is no direct equivalent that must appear before a noun in a sentence like this.

So:

• lệ phí can mean the fee, a fee, or just fees, depending on context.

The listener understands the exact meaning from the situation. If needed, Vietnamese can add words to make things more specific, but it usually does not need articles the way English does.

By itself, Tôi thanh toán lệ phí does not show tense clearly. Vietnamese verbs do not change form for present, past, or future the way English verbs do.

So this sentence could mean different things depending on context:

• I pay the fee
• I am paying the fee
• I paid the fee
• I will pay the fee

If you want to make the time clearer, Vietnamese often adds time words or aspect markers:

• Tôi đang thanh toán lệ phí. = I am paying the fee.
• Tôi đã thanh toán lệ phí. = I paid / have paid the fee.
• Tôi sẽ thanh toán lệ phí. = I will pay the fee.

Tôi is a neutral and polite way to say I, and it is a very safe choice for learners.

However, Vietnamese pronouns depend a lot on relationship, age, and situation. In real life, people often use other pronouns instead of tôi:

• em
• anh
• chị
• con
• cháu
• mình

In formal writing or when you do not know the relationship well, tôi is perfectly fine.

So in your sentence, tôi is correct and natural, especially in a neutral or formal context.

This follows the basic Vietnamese word order:

Subject + Verb + Object

So:

• Tôi = subject
• thanh toán = verb
• lệ phí = object

This is very similar to basic English word order:

• I
  • pay
    • the fee

That is one reason this sentence is fairly easy for English speakers to understand structurally.

Sometimes yes, but it depends on context.

Vietnamese often drops the subject when it is already obvious:

• At a payment counter, someone might simply say Thanh toán lệ phí in certain contexts, especially as a short note, instruction, or label.
• But as a full neutral sentence, Tôi thanh toán lệ phí is clearer.

So if you are learning standard sentence structure, keep tôi. In real conversation, subjects are often omitted when context makes them obvious.

Yes, it is a normal and understandable combination, especially in formal or official contexts.

You may see similar expressions such as:

• thanh toán học phí = pay tuition
• thanh toán viện phí = pay hospital fees
• thanh toán hóa đơn = pay a bill

That said, with lệ phí, many speakers also very naturally say:

• đóng lệ phí
• nộp lệ phí

In official contexts, nộp lệ phí is especially common when the idea is submit/pay a fee to an office or authority.

So your sentence is correct, but there may be other equally natural ways to say it depending on the situation.

Both can be translated as paying a fee, but the nuance is a little different.

• thanh toán lệ phí focuses on the act of making payment
• nộp lệ phí often suggests paying/submitting the fee to an authority, office, or official process

For example, in administrative situations, nộp lệ phí may sound especially natural:

• nộp lệ phí đăng ký
• nộp lệ phí visa

So if you are dealing with a government office, school, or formal procedure, nộp lệ phí is often very common.

A rough pronunciation guide:

• Tôi — level tone
• thanh — level tone
• toán — rising tone
• lệ — heavy/glottalized low tone
• phí — rising tone

Tone pattern matters a lot in Vietnamese, so be careful especially with:

• toán
• lệ
• phí

A rough English-style approximation is something like:

toy thanh twan lay fee

But that is only approximate. The tones and vowel quality are very important, so it is best to listen to native audio if possible.

Yes, but it sounds more formal than casual everyday speech.

A native speaker might say it:

• at a counter
• in an office
• in a formality-heavy interaction
• in writing
• when describing an official process

In more casual speech, many people would prefer:

• Tôi trả lệ phí.
• Tôi đóng lệ phí.
• Tôi nộp lệ phí.

So the sentence is grammatical and natural, but its style is on the formal side.