How to say “Politely express disinterest” professionally

Level 1: Thank you for considering me for this. While the initiative sounds valuable, my current commitments require my full focus to ensure existing project deadlines are met effectively. I recommend [Colleague's Name] who might have the capacity and relevant expertise.

Level 2: I appreciate you thinking of me for this, but my bandwidth is currently fully allocated to critical deliverables within our existing project roadmap. To ensure optimal resource deployment, perhaps we could revisit the overall strategic alignment of this new task against our current priorities during our next planning session?

Level 3: Understood. While this certainly falls outside my documented Q3 OKRs and current RACI matrix, I'm happy to 'explore synergies' if we can re-prioritize existing 'mission-critical' deliverables, perhaps by updating our agile sprint backlog and securing formal budget approval for the inevitable scope creep.

Level 4: I need to be direct: Taking on this additional task would directly compromise the successful completion of my current high-priority projects. If this initiative is paramount, we must formally re-evaluate my existing responsibilities and reallocate resources accordingly to prevent impact on our agreed-upon objectives.

Level 5: No.

Level 1: Thank you for this suggestion. We've noted your interest, and while it's an intriguing concept, it falls outside the agreed-upon scope of our current engagement. To explore this further, we would need to initiate a formal scope amendment process.

Level 2: We appreciate your vision and enthusiasm for expanding the project. However, our current focus must remain strictly on delivering the defined objectives within the existing Statement of Work. Diverting resources at this stage could impact the timely completion of our primary deliverables, which I'm sure we both want to avoid.

Level 3: Understood. We're always eager to 'add value' beyond the contractual obligations, but unfortunately, our 'value-add' budget for this quarter has been fully allocated. Perhaps we could 'pivot' to a new SOW, complete with revised timelines and a premium charge for 'exploratory development'?

Level 4: This request is outside the scope of our current contract. We cannot proceed with it without a formal change order and a revised agreement. Please let us know if you wish to initiate that process.

Level 5: Pay us more.

Level 1: Thanks for reaching out, but I'm currently fully focused on my assigned tasks and don't have the capacity to take this on. Have you tried [Another Coworker's Name] or perhaps checked the project's ownership matrix?

Level 2: I appreciate you thinking of me, but my current commitments are quite demanding, and I wouldn't be able to give this the attention it deserves. It might be more efficient to loop in someone whose current workload aligns better with this specific need.

Level 3: Interesting. While I'm always eager to 'foster cross-functional collaboration,' my current sprint objectives, as outlined in Jira, consume 100% of my designated bandwidth. Perhaps you could 'escalate' this to our manager for 'resource reallocation' if it's truly critical to your deliverables?

Level 4: I understand you need assistance, but this falls outside my responsibilities and I cannot take it on. My priority is completing my own work. Please refer to the project plan to identify the designated owner for this task.

Level 5: Not my job.