“Well,” you tell them, “I have another interview coming up in January. So I’ll let you know right after that.”
“Oh,” they say. “That might be a problem. We really have to know by December 31st. Can you let us know by December 31st?”
What you could do is answer the "When can you let us know?" question with another question "Well, when do you need to know?". Dec 31st might sound like they have some sensible end of year thing, but I predict scummy companies/recruiters will pick a date just before you said you had another interview. Try to see what they say first.
“Well,” you tell them, “I have another interview coming up in January. So I’ll let you know right after that.”
“Oh,” they say. “That might be a problem. We really have to know by December 31st. Can you let us know by December 31st?”
What you could do is answer the "When can you let us know?" question with another question "Well, when do you need to know?". Dec 31st might sound like they have some sensible end of year thing, but I predict scummy companies/recruiters will pick a date just before you said you had another interview. Try to see what they say first.