Which is a requirement for a lawyer when making a division of fees with another lawyer?

The requirement that the fee division must be proportional to the work performed is key to ensuring fairness in the distribution of fees between lawyers. This principle helps to maintain ethical standards within the legal profession by ensuring that each attorney is compensated in accordance with the contributions they made to the case or matter. This is particularly relevant when multiple lawyers collaborate on a case and helps to avoid potential conflicts or misunderstandings regarding the division of earned fees.

Additionally, while the other choices present various aspects of fee-sharing arrangements, they do not align with the ethical standards set by the Model Rules of Professional Conduct. For example, verbal consent from the client is not sufficient; a written arrangement is typically required, and the client must also be informed about the fee division. The notion that a law firm must be dissolved or that fees must be charged upfront does not reflect standard practice or requirements under the Model Rules, making the proportional division of fees the most relevant and correct answer in this context.