JohnJackson is right to be a little cynical of headhunters, but sometimes the bank wants the HH to do the work of getting a referee.It's a real pain for the HH, had one person where not only did the bank they'd worked for 5 years ago flatly refused to give a reference, but would not even budgewhen I told them that it was a different part of the same bank who was taking them on.You may of course feel that the HH has done a good job for you, and thus don't have a problem if they try to recruit your replacement for your old job.Given that they will have been looking at people rather like you for the new job, good chance they can quickly fill the whole created by your departure.Howevr, if you feel they are sharks looking for prey, then be aware that upsetting your referee by getting them loads of sales calls may not be to your advantage.It may not be the last time they act as a reference, and you don't want them annoyed for last time they gave a reference.Most firms "due dilligence" is covered by a simple note from HR saying "X worked here from X to Y as a Z"Thus if you give them the details for HR, they should be satisfied. At a number of firms you need 5 years seamless references, else you simply cannot start work there even if there is anoffer.Be aware that most offer letters are carefully crafted not to be in any way a commitment and typically say "subject to references".Occasionally a manager will really want to talk to your old boss, not that common but happens.In which case you ask their permission first. Providing you are leaving with some grace, most will agree. Again if you are worried abour the HH, ask for the new manager's contact details and ask your old boss to contact them. This may work better, since it is one thing to ring someone at a time of your choosing, and another to be rung when one is busy.