Additional Payments to Mortgage Principal

I pre-paid some of my mortgage principal last week-- unfortunately, I didn't do it on purpose!

My payment due March 1 was the first one with a new, higher escrow amount due to the ongoing tax abatement confusion. I entered all of this correctly in Quicken, but I forgot to change the auto-pay amount I have set up to go out of my checking account! I was looking at my account online and saw that the amount debited didn't match my Quicken records. I realized what had happened and immediately thought I'd better send another payment to make up the balance. So I sent the missing $370 by an immediate electronic payment.

Can you say "dumb and dumber?"

AFTER doing this, I logged onto the CitiMortgage website to look at the status of things. I'd never actually used their site before, so I enrolled right then. Nice site, easy to get all your info: it only took me seconds to discover that because the amount of my original payment didn't match my official amount due, and didn't arrive with a payment coupon in the mail designating how it was to be applied, they considered the whole thing to be an additional payment toward the principal, instead of applying it first to the interest, then principal, then tax escrow. And of course this is exactly what will happen with the additional $370 too! So in order to fix things, I went back to my checking account and sent a third payment for the exact amount that was originally due on my mortgage statement. Let's hope they know what to do with it this time!! And let's hope it's close enough to the due date that they don't charge me a late fee.

Oh well. I was lucky enough to have the cash on hand to pay extra on the mortgage this month. I'd been thinking I might not make any extra payments towards my principal just yet since my interest rate is pretty low vs. potential investment returns, and I'm still rebuilding my liquid savings after buying the condo. But I figured it would eventually be good to pre-pay a little here and there, as I really like the idea of paying less interest over the life of the loan. So I was really waffling about it. Isn't it nice when decisions are made for you, even when what makes the decision is your own stupidity???