Ambiguous numbers in contract: which will be deemed to be valid (if so)?
<p>An employment contract states that notice of resignation (edit: or termination) should be given</p>

<blockquote>
  <p>30 (sixty) days</p>
</blockquote>

<p>prior to end of employment. Clearly, the number represented by the digits contradicts the number given in words. Which of the two should prevail (and why)? Or will the containing clause be deemed invalid?</p>

<p>The text is in a word processor format file (editable). Jurisdiction: South Africa. In the past, in my experience, employment contract in this field (and many others) specified a notice period of 30 days / 1 calendar month, so I see that as a sort of "norm". Although I have seen a 6-week notice period in the recent past, so maybe there is a trend towards longer notice periods.</p>

<p>(As an aside: I can see the value of this practice (giving a number both in digits and spelling it out) when a document is hand-written (or faxed) and may be unclear, but in the age of the electronic documents and e-mail???)</p>

<p>The general principle is that when one party writes a contract, and there is an ambiguity, the ambiguity is interpreted against the interest of the writer (<a href="https://en.wikipedia.org/wiki/Contra_proferentem" rel="nofollow noreferrer">contra proferentem</a>). The case of <a href="http://www.saflii.org/za/cases/ZAGPJHC/2012/2.pdf" rel="nofollow noreferrer">Hypercheck v. Mutual and Federal Ins</a>. confirms that South African law operates under this doctrine.</p>

<p><a href="https://english.stackexchange.com/a/11992/152553">This answer</a> to a similar question (<a href="https://english.stackexchange.com/questions/2152/why-are-numbers-usually-written-twice-in-contracts">Why are numbers usually written twice in contracts?</a>) on English Stackexchange leads me to believe that the number written out as words take precedence over numbers written in digits (caveats: United States, and checks not contracts).</p>

contract-law south-africa