The internal memo is part of your proposal

Your sponsor may have to explain the purchase to people you will never meet. A proposal designed for a live presentation can fail in that setting because the reasoning depends on your narration.

Give the sponsor a concise decision memo. It should state the problem, why it matters now, the options considered, the recommended approach, cost, risks and the decision required. The memo should make sense without the original conversation.

Do not write an internal advocacy document that hides uncertainty. Your sponsor will be more exposed if colleagues discover omitted costs or dependencies. A balanced memo helps them answer difficult questions honestly.

Different readers need different details. Finance may focus on assumptions and timing, operations on disruption, and users on workload. The core recommendation should remain consistent while supporting material addresses those concerns.

Ask the sponsor which objections are likely and which terms their organisation uses. Adapt the document without inventing consensus. If an important stakeholder has not been consulted, mark that as a remaining step.

The seller's responsibility is to make the recommendation intelligible and defensible. The sponsor's responsibility is to judge whether it fits the organisation. Supporting that judgment is more durable than supplying a persuasive script that collapses under scrutiny.