Short answer. Generally no. Article 1802 says that where it was stipulated that none of the managing partners shall act without the consent of the others, the concurrence of all is necessary for the validity of the acts, and the absence of any one cannot be alleged — unless there is imminent danger of grave or irreparable injury to the partnership.
What the law says
In case it should have been stipulated that none of the managing partners shall act without the consent of the others, the concurrence of all shall be necessary for the validity of the acts
Civil Code, Article 1802 — Unanimity-Required Management. Read the full provision →
What the law says
the absence or disability of any one of them cannot be alleged, unless there is imminent danger of grave or irreparable injury to the partnership
Civil Code, Article 1802 — Unanimity-Required Management. Read the full provision →
Unanimity means all must concur
Article 1802 takes your stipulation seriously. It provides that In case it should have been stipulated that none of the managing partners shall act without the consent of the others, the concurrence of all shall be necessary for the validity of the acts. When your agreement requires the managing partners to act unanimously, that requirement controls: an act is valid only if every one of them concurs. A single managing partner cannot bind the firm on his own where you have all agreed that none may act without the others' consent. The phrase 'concurrence of all' is exacting — it means the agreement of each managing partner, not a majority.
Absence is not an excuse
The heart of your question is the absent partner, and the article addresses it head-on. It states that the absence or disability of any one of them cannot be alleged as a reason to proceed without him. So the fact that one managing partner is away, unreachable, or temporarily unable to act does not relax the unanimity rule. You cannot say 'he was absent, so the rest of us acted' and treat the act as valid. The law refuses to let the requirement of unanimous consent be worked around simply because gathering everyone is inconvenient. If unanimity was stipulated, an absent partner's silence is not consent.
The emergency exception
There is one narrow escape valve. The requirement of concurrence, and the bar on alleging absence, apply unless there is imminent danger of grave or irreparable injury to the partnership. Where waiting for the absent partner's consent would expose the firm to serious, imminent and irreparable harm, a managing partner may act to protect it. This is a true emergency exception, not a general convenience. The danger must be imminent and the threatened injury grave or irreparable — a looming loss the partnership cannot undo — before one partner may lawfully act alone in the face of a unanimity clause.
What happens to acts done without concurrence
The consequence of ignoring the rule is significant. Because the article makes concurrence of all necessary for the validity of the acts, an act taken by one managing partner without the others' consent — outside the emergency exception — lacks validity as a partnership act. This protects the partners who insisted on unanimity from being committed to decisions they never approved. If you agreed that no managing partner acts alone, you are entitled to hold that line: absent a genuine emergency, a co-manager who acts while another is away has not validly bound the firm.