Why You Still Need to Spell Out Numbers Sometimes
Writing numbers in words looks like a formality from another era, and in two places it is still doing real work. The Number to Words Converter spells out any number in plain English.
Where it prevents fraud
A cheque carries the amount twice - in figures and in words - and that redundancy is the point. Figures can be altered: a 1 becomes a 4, a decimal point moves, a zero is appended. Words are far harder to change convincingly, and a mismatch between the two is detectable.
Where they disagree, the written amount generally prevails in most jurisdictions, which is precisely why it exists. The same reasoning appears in contracts, where a sum is often given as "five thousand pounds (5,000)" - the words are the authoritative version and the figure is the convenience.
Legal and financial documents follow the same pattern for the same reason: the harder a number is to tamper with, the better.
Where it is a style rule
Most style guides ask for numbers under ten in words and ten upward in figures, though the cut-off varies - some use 100, and news style often differs from academic style.
Two rules are near-universal. Never start a sentence with a figure: write "Twenty-three people attended", not "23 people attended", or rephrase so the number is not first. And keep a comparison consistent - "between 5 and 20", not "between five and 20".
Round numbers read better as words in prose: "about a thousand people" rather than "about 1,000 people". Precise numbers read better as figures.
The style points that catch people
Hyphenate twenty-one through ninety-nine. Not the hundreds: "two hundred", no hyphen.
British English inserts "and" after hundreds - "one hundred and twenty-three". American English omits it - "one hundred twenty-three". Both are correct in their own convention and worth being consistent about within a document.
No "and" before the tens otherwise: "two thousand four hundred", not "two thousand and four hundred".
For currency, the convention is "five thousand pounds and fifty pence", or on a cheque the fractional part is often written as a fraction - "and 50/100".
The large-number trap
A billion means a thousand million in modern usage everywhere in English, including Britain, which switched officially in 1974. Older British texts and some European languages use the long scale where a billion is a million million, so a historical document may mean something a thousand times different from what it appears to.
If a number crosses that boundary and matters, spell it out or state the digits.
Common questions
How do I write a decimal in words?
"Three point one four", reading the digits after the point individually.
What about ordinals?
First, second, third in words under ten; 11th, 42nd in figures above. Same threshold as cardinals.
Does it matter for accessibility?
Screen readers handle both, and they read some formats oddly. Figures are fine; it is dates and phone numbers that benefit from care.
Is it needed on an invoice?
Not usually, though a written total on a large invoice is a sensible precaution - the Invoice Generator covers the rest of the fields.
Got a number to write out?