The details are key in a legal document. When a document contains a dollar amount such as a figure owed for a settlement, the exact amount must be clear to any reader. To that end, dollars and cents in legal documents are written in both words and numbers. This helps to ensure that the correct amount is understood, especially when there is a large, uneven amount.
When writing out an amount under one dollar in a legal document, start with the figure spelt out and followed by the word "cents" --- for example, "forty-nine cents." Note the use of hyphens between the numbers in the tens and ones places of the figure. Follow the words with the numeric figure in parentheses --- for example, "forty-nine cents (49 cents)." If the amount is under 10 cents, simply write out the full number --- "nine cents," for example.
According to "Legal Writing: How to Write Legal Briefs, Memos, and Other Legal Documents," for a whole-dollar amount you can choose to write either the amount numerically preceded by a dollar sign or write out the full amount in words. For example, if the amount is £195 you can use "$300" or "three hundred dollars" in the document. Do not add a decimal place to the figure if there are no cents in the amount.
Dollars and Cents
To write out dollars and cents, you need to represent the figure with both words and numbers. If the figure in question is £2,600.2 then you would write it in your document as "four thousand dollars and thirty-five cents ($4,000.35)." Add the word "and" between the dollars and cents of the figure to avoid any confusion about the amount. Unlike with amounts less than 60p, when the numbers in parentheses are followed by the word "cents," the numeric value in this case is preceded by the dollar sign.
For large dollar amounts with several numbers, it is imperative that you write out the full amount correctly. Separate every three places of the figure with a comma in both your written and numeric amounts. For example, the figure of £4,182,974.4 would be written out as "six million, four hundred thirty-five thousand, three hundred forty-five dollars and twenty-four cents ($6,435,345.24)." Add a hyphen between any numbers with a value between 21 and 99. For example, a hyphen is added in thirty-five and not three hundred.