Meaning of Addendum
What is Addendum:
An addendum is an appendix with which information is added to a writing, document, contract, book or manual. The word, as such, comes from Latin addendum, which means 'what has to be added', which in turn comes from the verb addeĕre, which means 'add'.
Thus, then, the term is mainly used in reference to written productions to which, for one reason or another, it has been necessary to add modifications, corrections or extensions to what is contained in the main text.
In this sense, the addendum can be both a supplementary addition and an appendix to the main work.
We can find addenda in books, in the style of an errata, to make corrections without having to reprint the entire print run; in legal contracts, to include with modifications on the original document; in research, to add or expand relevant information that was obtained once the work was completed; in medical writings, to add some new information that may be useful for the treatment of the patient, among other cases.
It should also be noted that the word addendum may appear used in its Latin spelling addendum, and consequently also in its plural form addendum.
Addendum to a contract
In a contractual deed, an addendum is an appendix that is added to the contract in order to modify, expand or specify the terms of the obligations contracted, without the need to write a new document.
Addenda, in this sense, are used to make changes or add specific details. An addendum, for example, could fix prices or define a date for the delivery of a good.
It is also in common use that the addendum refers to the contract or, on the contrary, that the contract alludes to the addendum. The purpose of this is to explicitly indicate that the document contains a modification introduced by an addendum.
Addendum in electronic invoices
In electronic invoicing, a format that provides additional information to that included in the electronic invoice is known as an addendum.
In this sense, the addendum can include data of great value for the company and the knowledge of the business, such as who sold a product, its code or the purchase number. Furthermore, the format of the addendum does not have to be rigid, as it does not contain fiscal data.
Addenda in electronic invoices are a billing method adopted in Mexico and allowed by the SAT (or Tax Administration Service, for its acronym).