What are you doing next? Are you taking a new job right away, or leaving the workforce for a while/indefinitely? If you're starting a new job right away the lump sum can give you some more money compared to if you take the vacation and push your start date out at the next place. On the other hand if you don't have any immediate plans to work elsewhere, using the vacation and then giving notice afterward can often be optimal. Especially when you have five weeks worth...you'll get an extra month or two of company-subsdized health care, you'll accrue some amount of additional vacation while you're on vacation, and there might even be a paid holiday or two in there. None of that happens if you just quit and have them give you a lump sum for your accrued vacation. The trade-off is that you have to pencil in a couple weeks in the office tying up loose ends during your notice period after you've already taken over a month away. You might prefer to just be done, take the lump sum, and get an earlier start on the next part of your life even if that choice leaves you slightly less wealthy.