Should I tell my manager I'm interviewing for other jobs?

Twelve years of placements have given me a clear pattern on this. Candidates who tell their manager they're interviewing before they have an offer almost always regret it. Even with a supportive manager, you've changed the relationship. You're now flagged in their head as a flight risk, which affects how they allocate stretch projects, how they invest in your development, and how visible you are when promotion conversations happen behind closed doors.

The specific risks. Some managers, when told you're interviewing, will accelerate finding a backfill — meaning you no longer control the timeline. Some will quietly move stretch projects away from you. Some will mention it 'in passing' to their own manager, which becomes corporate gossip you can't control. Some will simply pull back emotionally, which makes the rest of your tenure unpleasant whether you stay or leave.

The legitimate exceptions are narrow. If you have a genuinely strong relationship with a manager who has actively supported your growth, who has said in past conversations 'I want to help you build the career you want even if that means leaving here', then a frank conversation can work — particularly if there's a credible internal opportunity that might be created. If your industry has a specific cultural norm around openness about ambitions (some scale-ups, some non-profits), the calculation can differ.

Outside those exceptions: silence until offer signed and start date in writing. Then tell your manager in person, briefly, with your notice period and a draft handover plan. 'I've accepted a role at [company]. My last day, based on contract, is [date]. I'm committed to a clean handover.' Five minutes. Don't elaborate. Don't get drawn into 'what could we have done to keep you' — the answer is 'I appreciate the question, but I've made my decision.'

The mistake to avoid: telling your manager out of guilt or because you think they 'deserve to know'. They don't. Your contract entitles your employer to your notice period and a handover. It does not entitle them to early visibility into your career planning. The ethical line is the formal notice period, not the pre-decision phase.