The two acts work differently
Jurat: you must sign in the notary’s presence, and you swear (or affirm) that the contents are true. A document that arrives pre-signed for a jurat has to be signed again in front of the notary — which some receiving agencies won’t accept on an already-signed page.
Acknowledgment: you may sign in advance. What you’re doing before the notary is acknowledging that the signature is yours and that you signed willingly. Pre-signing is legally fine here — the notary still verifies your identity in person.
So why not just check which one you need?
Because the answer lives with the document, not the notary. Which certificate a document requires is determined by the receiving agency, the document’s own pre-printed notarial wording, or your attorney. California notaries are specifically prohibited from choosing the act for you — that would be legal advice. If your document already contains notarial wording, the act is usually spelled out there; if it doesn’t, ask whoever will receive the document.
The practical rule I give every caller
Bring the document complete but unsigned, unless the receiving agency told you otherwise in writing. Worst case with an unsigned acknowledgment: you sign at the table, thirty seconds. Worst case with a pre-signed jurat: a re-signed page, a confused receiving agency, or a second appointment. Waiting costs nothing; guessing sometimes does.
One more nuance: loan packages
Real estate and loan documents come with lender instructions that spell out exactly where and how to sign — and they’re signed at the appointment, page by page, with the signing agent keeping order. That’s the core of what a loan signing agent does.
General information about California notary practice, not legal advice. For questions about your specific document, contact the receiving agency or an attorney.