If an Oath is a separate and independent notary act, you can charge for it as far as I know — I swear!

But, I believe (and please comment below if I am wrong) that you may not charge extra for an Oath on a Deposition, court appearance, or for credible witnesses.

When using credible witnesses for an Acknowledgment, you just charge for the Acknowledgment, but not for the credible witnesses. This is only for states that allow credible witnesses which is about 30 states more or less and you can look them up online.

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When are you required by law to give Oaths?
http://blog.123notary.com/?p=21017

The Starbucks Oath Question
http://blog.123notary.com/?p=21001