Can we apply for H4, though the H1 holder haven't traveled to US yet (nearly an year)

I got H1 nearly an year back and haven’t traveled yet to US. Recently i got married and looking to apply for H4. My employer suggesting not to do now as I haven’t traveled yet and it might effect my H1 and asking me to wait till I move to US and work for a month or so, then to apply.

Is it true? Will it be a problem if we apply for H4 now?

Congratulations on your wedding. Your employer is misinformed. There is no effect across categories. However, please make sure that as an H-4 applicant, your spouse H1B sponsor has no prominent red flags such as poor reputation or questionable salary bases.