Hello there, Relewiswelding.
I'm here to assist you in paying your taxes.
EFTPS will send you a letter indicating the PIN via mail if you're pre-enrolled when you applied for your EIN. If you didn't receive it or you forgot your PIN, you may contact them and they'll resend it to you by U.S. Mail.
Please visit https://www.eftps.gov/eftps/direct/FAQGeneral.page and click on I can't find my PIN. From there, you'll see the number that you can call.
I've added this article for your reference in paying federal estimated quarterly taxes.
I'll be here if you have more questions about taxes. Wishing you all the best and take care!
