Yes, you can pay only the agreed amount under the confirmation plan off early, but there's a right way and a wrong way to do it.
If you want to make an extra payment from time to time, that's fine. If you plan to make a large, lump sum payment, you should consult your attorney first.
The first question your attorney and the trustee will ask you is where the money is coming from to pay off the Chapter 13. If the money is coming from a loan (even a loan from a family member) you need to seek court approval of that borrowing first. The source of the funds is also important to determine whether the amount you proposed to pay to your creditors in the first place is still fair.
Attorney
10 + years experience in civil litigation, jury trials, and business law;