EFTPS payment form

If you mean that you have a single-member LLC, the LLC is disregarded for income tax purposes. It is treated the same as if you had your own business without an LLC. You report your business income and expenses on Schedule C in your personal tax return. So you make the estimated tax payment the same as if it were for personal income such as investment income. The form that you use is Form 1040-ES. You use your Social Security number for the estimated tax payment, even if you have an EIN for the business.

If your LLC has more than one member, or if you filed an election with the IRS to treat the LLC as a C corp or S corp for tax purposes, post more details.