Have you ever written “instalments” and wondered whether you should have written “installments” instead? Or perhaps you’ve seen both spellings and assumed one must be a mistake. The good news is that Instalments or Installments is not really a question of right versus wrong. Both spellings are correct; the difference is mainly regional.
Instalment is the standard spelling in British English, while installment is the standard spelling in American English. Both words have exactly the same meaning: one of a series of payments or portions delivered at different times.
So, if you’re writing for a British audience, use instalment. If you’re following American English, use installment.
Let’s look at the difference in more detail.
Instalments or Installments: What’s the Difference?
The only difference between instalments and installments is the spelling.
| Spelling | English variety | Example |
| Instalment | British English | I paid the first instalment yesterday. |
| Installment | American English | I paid the first installment yesterday. |
| Instalments | British English plural | The cost can be paid in monthly instalments. |
| Installments | American English plural | The cost can be paid in monthly installments. |
The meaning does not change.
Both spellings refer to a portion of a payment, debt, series, or work that is completed or paid at a particular time.
Instalment in British English
In British English, the preferred spelling is:
instalment
For example:
You can pay for the course in six monthly instalments.
You’ll generally see this spelling in British English publications and in countries where British spelling conventions are commonly followed.
Installment in American English
American English generally uses:
installment
For example:
You can pay for the course in six monthly installments.
The extra l is the main spelling difference.
What Does Instalment or Installment Mean?
An instalment or installment is one part of something that is paid, delivered, or completed over a series of separate stages.
The word is especially common when discussing money.
For example:
She paid the first instalment of the loan.
This means she made the first payment toward the total amount owed.
However, the word isn’t limited to financial payments. It can also refer to one part of a larger series, such as a book, movie, story, or television program.
For example:
The latest installment of the film series was released last week.
Here, installment means one entry in a continuing series rather than a payment.
Instalment vs. Installment in British and American English
The difference follows a familiar pattern between British and American spelling.
British English often retains spellings that differ slightly from their American counterparts.
For example:
- colour → British English
- color → American English
- favour → British English
- favor → American English
- centre → British English
- center → American English
- instalment → British English
- installment → American English
This doesn’t mean one spelling is more correct than the other. They belong to different standard varieties of English.
Why Does American English Use “Installment”?
The spelling installment developed as the standard American form, while British English retained instalment.
The difference is particularly noticeable because the word is related historically to install, which contains two l’s.
As a result, it can feel natural to assume that installment must be the only correct spelling. However, British English traditionally uses instalment with one l in the middle.
This is one of those spelling differences that becomes much easier once you know the regional pattern.
Instalment or Installment: Which Should You Use?
The best spelling depends on your audience.
Use “Instalment” When:
Use instalment if you’re following British English conventions.
This is appropriate for writing intended for audiences using British spelling, including many publications and institutions in countries where British English is the standard or widely used.
Example:
The remaining balance will be paid in three equal instalments.
Use “Installment” When:
Use installment when writing in American English.
Example:
The remaining balance will be paid in three equal installments.
If you’re writing for an American website, publication, company, or audience, installment is generally the expected spelling.
Instalments or Installments in Financial Writing
The word appears frequently in financial and consumer contexts.
You may see it when discussing:
- Personal loans
- Car payments
- Mortgages
- Credit purchases
- Tuition payments
- Payment plans
- Subscription arrangements
- Business financing
- Debt repayment
For example:
The customer agreed to repay the amount in twelve monthly installments.
This means the total amount will be divided into twelve payments.
Example of an Instalment Payment
Imagine a product costs $1,200 and a customer agrees to pay for it over 12 months.
Ignoring interest and additional fees for simplicity:
$1,200 ÷ 12 = $100
The customer would pay $100 in each monthly instalment or installment.
The spelling changes according to the variety of English, but the financial concept remains exactly the same.
Instalment or Installment in Everyday Writing
The word isn’t only used in formal financial documents.
You might encounter it in everyday conversations and entertainment writing.
For example:
I bought the laptop in monthly instalments.
Or:
The newest installment in the series was surprisingly good.
Notice that the second sentence doesn’t refer to money at all. Here, installment means one part of a larger series.
Installment Can Mean More Than a Payment
One important point about this word is that installment/instalment has more than one common use.
1. A Payment
The most familiar meaning is a payment made as part of a larger total.
Example:
I made my final installment payment today.
2. A Part of a Series
It can also mean one part of a continuing series.
Example:
The third installment of the popular game introduced several new characters.
In this context, the word means the third entry or part of the series.
3. A Portion Delivered in Stages
The word can sometimes refer to something supplied or completed in separate portions.
For example:
The report will be published in several instalments.
Here, the information is being released in stages rather than all at once.
Common Examples of Instalment and Installment
Here are examples using both spelling conventions.
British English Examples
- The loan will be repaid in monthly instalments.
- I have already paid the first instalment.
- The final instalment is due next month.
- The magazine published the story in several instalments.
- The television drama returned for another instalment.
American English Examples
- The loan will be repaid in monthly installments.
- I have already paid the first installment.
- The final installment is due next month.
- The magazine published the story in several installments.
- The television drama returned for another installment.
The meanings remain unchanged.
Instalment or Installment: Singular and Plural Forms
The spelling difference also appears in the plural forms.
British English
- Singular: instalment
- Plural: instalments
Example:
The first instalment is due today.
The remaining instalments are due monthly.
American English
- Singular: installment
- Plural: installments
Example:
The first installment is due today.
The remaining installments are due monthly.
The plural is formed normally by adding -s.
Is “Instalment” Incorrect?
No. Instalment is not an incorrect spelling.
It is the standard British English spelling.
Similarly, installment isn’t incorrect. It is the standard American English spelling.
If you’re proofreading someone’s writing, you should consider the variety of English they’re using before changing one spelling to the other.
For example, changing every instance of instalment to installment in a British English document isn’t necessarily correcting an error. It may simply be changing the document from one spelling convention to another.
Is “Installment” Incorrect?
No. Installment is also completely correct.
It is the standard spelling in American English.
So the answer to “Instalments or Installments?” is:
Both are correct. Choose the spelling that matches your variety of English and remain consistent.
Common Mistakes With Instalment and Installment
Because the two spellings are so similar, writers sometimes make mistakes when switching between British and American English.
Mistake 1: Mixing Spellings
A document might use:
The first instalment is due today.
and later say:
The second installment is due next month.
Neither word is individually wrong, but mixing spelling conventions can make the writing look inconsistent.
Choose one variety and stick with it.
Mistake 2: Assuming One Is a Typo
Seeing instalment in a British English document doesn’t mean someone forgot an l.
Likewise, seeing installment in American English isn’t a spelling mistake.
Mistake 3: Confusing the Meaning
Remember that an installment doesn’t necessarily mean a payment.
It can also refer to one part of a series.
For example:
The latest installment in the movie franchise was released this year.
No payment is being discussed.
Instalments or Installments in Formal Writing
If you’re writing a formal document, consistency matters more than choosing one spelling universally.
For example, a British English business document might say:
The outstanding balance must be paid in four equal instalments.
An American English business document might say:
The outstanding balance must be paid in four equal installments.
Both sentences are grammatically correct.
The important thing is to follow the spelling conventions appropriate for your intended audience.
How to Remember the Difference
Here’s an easy memory trick:
British English → instalment
American English → installment
Think of the extra l in installment as part of the American spelling.
You can also remember the two forms as:
UK: one L
US: two Ls
This is a simple shortcut, although it’s best to remember the words as part of the broader British-American spelling difference.
Instalments or Installments: Quick Comparison
| Question | Instalment | Installment |
| Is it correct? | Yes | Yes |
| Main variety | British English | American English |
| Meaning | A portion or payment | A portion or payment |
| Singular | Instalment | Installment |
| Plural | Instalments | Installments |
| Financial use | Yes | Yes |
| Series/entertainment use | Yes | Yes |
Frequently Asked Questions
Is it instalment or installment?
Both spellings are correct. Instalment is the standard British English spelling, while installment is the standard American English spelling.
Is “instalments” British or American?
Instalments is the British English plural form. American English uses installments.
Is “installments” correct in English?
Yes. Installments is the standard American English spelling and is completely correct.
What is the difference between instalment and installment?
There is no difference in meaning. The difference is spelling: instalment is generally British English, while installment is American English.
Which spelling should I use in a formal document?
Use the spelling that matches your intended audience and the English variety used throughout the document. The most important thing is consistency.
Does installment only refer to money?
No. An installment can also mean one part of a series, such as a movie, book, television program, game, or story.
For example:
The latest installment in the series was released last month.
What is the plural of instalment?
The British English plural is instalments.
What is the plural of installment?
The American English plural is installments.
Is instalment one word or two?
Instalment is one word. Installment is also one word.
Can British English use installment?
You may encounter installment in British contexts, particularly because American English is widely encountered internationally. However, instalment is the traditional standard British spelling.
Conclusion: Instalments or Installments?
So, when it comes to Instalments or Installments, there isn’t a single spelling that is correct for every English speaker.
Instalment is the standard British English form, while installment is the standard American English form. Both refer to a portion of something, particularly a payment made as part of a larger amount, but the word can also describe one part of a series.
The easiest rule to remember is:
British English: instalment
American English: installment
If you’re writing for a specific audience, follow that audience’s spelling convention. Most importantly, stay consistent throughout your article, document, or website.
Once you know this small British-versus-American spelling difference, you’ll never have to second-guess instalments or installments again.
