I have a document that will eventually require two different types of authentication - both an apostille and Taiwanese authentication. The document itself would be expensive and difficult to replace or to obtain a second original copy of. Does having one type of authentication certificate affixed to it invalidate it for another type of authentication? If so, what is usually done in this situation?
I have a document that will eventually require two different types of authentication - both an apostille and Taiwanese authentication.
These are sequential. The authentication is the primary event. Another name for an authentication (which is slightly more general) is a notarization. An apostille authenticates the authentication, verifying that, for example, the notary who authenticated a document was a genuine notary in good standing.
The purpose of an apostille is to prevent someone unfamiliar with foreign notarization from using a fake notary stamp to defraud someone abroad. This is done by having the notarization's validity confirmed by a single government office in the country where the notary is purportedly commissioned. Then, foreigners relying upon the document need only confirm that the single government office that carried out the apostille is bona fide. This could be done, for example, by getting on the phone with that government office.
For what it is worth, one of my very first cases as a lawyer involved authenticating a long chain of Taiwanese deeds to real estate located in New York State, since the deeds had never been recorded in New York State real property records, for real property previously owned by former President Millard Fillmore (before he served as the 13th U.S. President). The chain of title also contained an affidavit that Millard Fillmore didn't have anyone who could claim to be his common law wife at the time.
I think that the information provided by @ohwilleke is pretty accurate.
Considering that you did not specify where are you going to do the authentication, perhaps it would be relevant to share a particular situation that happened to me.
A few years ago I needed to authentication a document to send to another country. However, my country was not part of the Hague Apostille Convention at the time. So I went to the consulate of the receiving country and had the document authenticated by the Consular Officer.
Later, in a different situation, but at the same receiving country, I was required to present that document again, but it was necessary to have the Apostille. So I got the first document already authenticated by the Consulate back to my home country and had it authenticated with the apostille.
In the end, I have a document with both authentications, but due to a particular situation with my home country.
Nowadays, I know that it is not possible anymore to have the Consulate authenticate a document, only through the apostille.