A headhunter doesn't want to work with me unless I tell him all the places I interviewed/am interviewing with. His justification is that he needs to know whom to avoid approaching on my behalf. Does that sound valid, or should I seriously avoid giving out such information?

Avoid.He is just fishing for information to send his candidates there.He can give you the name of bank and desk he is sending resume to and you can tell him whether or not you have spoken to them.

Agreed with AD. I mean, that kind of information is precious for him and it's free for you to share, but definitely not with this kind of guy. In fact, you don't want to work with this kind of guy at all.

Avoid. Flat out refuse, even if they are insistent. Just tell him/her that you do not discuss your current applications with anyone other than the recruiter who set your interview up. Most will say they get it and leave it at that. But some will be really insistent, and with those you really don't want to work. As AD said, just ask them which role they have in mind (possibly get a job ID/ref nr as well) and double check if your CV is already there.

Spice, you may know that I'm a headhunter and I'm here to say that not only is this fishing, it is the act of bad headhunter.Their immediate response will be to send competing candidates to those managers, sometimes mentioning that you told them. This has the effect of reducing your chances and pissing off people who might hire you.As AD says, saying the name of the bank is fine since it's not enough to cause you trouble.However, asking for job ID number isn't going to work with a dodgy HH since they can just make one up.The polite way to refuse is "I was given this info in confidence by the other HH and I will respect that confidentiality just like I will respect yours".However in this case I'd just tell her to fuck off.

Thanks everyone for all your advice. The roles I'm applying for are quite narrow, so I don't even feel comfortable mentioning just the names of the banks.

It has to be pretty damned narrow for that to be true, but if you are that specialist then that's the way to cut it.That increases the risks that the HH will send someone to compete with you, since the more specialist you are, the more your value is driven by rarity.If only a tiny number of firms want your skillset, then it follows that your competitors are rare and just one CV from this HH could seriously impact what they offer, even if you are better than them.