a couple of adverts I have missed (in fact he just checked with me this morning about whether I was going for something that came up today). I've always done this with bosses in the past and it's been the best tactic. It means everybody knows where they stand and there are never any hard feelings. At my first job, when I'd been there a while and was beginning to look to move on, a fantastic opportunity came up elsewhere. My then boss agreed it was a great opportunity and actually helped me with my application (yes, I got the job) For a first-round interview, I would keep it to myself and book it as holiday, either half a day (although MrPerfect's point about having to spruce yourself up beyond what is usual definitely makes sense to me) or a full day. If you don't have any annual leave left or will not be allowed to take the time off when you need it, then you may need to come clean about it to your boss, but it is worth seeing if you can do early morning/late evening and plead an appointment that you have to come in late/leave early for. The point at which I would tell my boss was if I was called back for second round. At that point, you know you are properly in the running for the new job and it gives your current boss the chance to put wheels in motion to keep you,