Disclaimer: I'm not a financial advisor or a professional in the industry. However, I have studied and researched my Credit for a long time and can offer my experiences/insight. I'm 29 years old with excellent credit that I've built over several years.
*Quick story: I apologize if I say anything that sounds obvious. I ASSUME no one actually understands the complexity of how credit works, as I've spoken with at length with Experian, Equifax, and TransUnion, and they openly admit they're not always sure how their credit reporting is used or interpreted by lenders, nor is it their job to know. Their methods of "scoring" are also proprietary, and as such your credit report can and will be different, and you can and will have different scores based on that information--on formulas designed and owned independently by each bureau. Also, there are something like 49 bureaus today, not just the 3 you've probably heard of. WITH THAT SAID, here are my thoughts on your late payment.
*If you spoke with your lender, It's highly unlikely they'll remove the ding on your report. They put it on in the first place. It's not a mistake to them, and they can't be bothered to correct it. You're welcome to try, but I'm hoping my followup points will make you feel a little better.
*Not all bureaus will care to keep track of this information. But if you spoke with one, it takes 7-8 years before they'll remove a late payment mark from your report. You can sometimes get this done early. They will not remove it without you calling to ask (in other words, there is no "8 year mark" where it suddenly disappears)
*Generally, 1 late payment will not severely impact your score, or your report, which is technically more important.
*Credit scores are NOT a "grade" so to speak. Think of it like currency. You EARN credit points for things like: 1) High Credit to Debt ratio (keeping balances low) --lots of impact 2) average length of credit history (most important with credit cards) --some impact 3) little to no derogatory marks -- a big deal if you have lots, not such a big deal if you have a few 4) having multiple accounts, as well as diversity of accounts, so long as they're not opened back to back (so having a student loan that you pay on time, a mortgage, a car payment, and 3 credit cards can be a good thing if you're managing them)
*When you open a new line of credit (a loan, a new home, a credit card) you SPEND some of that credit. As you have time with that line of credit, you EARN some credit (see above)
*When lenders look at your report, they all look for different things. There is absolutely no uniformity, no clear rule to how they'll view your report. There's no magic number of "No more than 3 credit cards" or "no more than 20% credit utilization" etc. There's no magic Credit Score target, though I've heard it's commonly accepted that if you have 740 or higher on any type of Fico, you should qualify for the lowest interest on any home mortgage.
*Notice I said "any KIND of Fico". Bureaus actually have different proprietary Fico scores. An Experian Rep told me they use one they call Fico 8. Okay?...lol
*Credit scores can change DAILY. Really, they can. I'm not saying they do, but they can change for ANY reason. These scores were described to me by a TransUnion rep almost as though intellectual, private property, so it's my approach to treat them just as they are: important to care if it's good or bad--not important to care about HOW good or HOW bad...
PERSONAL EXPERIENCE *When I was in college I opened my first credit card under a "0% APR for 1 year promo". I thought that meant I didn't have to pay the monthly minimum. Obviously, it doesn't. I went 90 days without paying my minimum before I caught on, and only 2 years ago got it removed from my report.
During the 7 to 8 years I had it on, I built my Credit Score from 680-700 range to 750s-760s (Depends on the report/bureau/if there's a fart in the breeze) Please note, my lower range was due to more money owed on student loans, lower average length of credit, MUCH lower Credit line (and therefore higher debt to credit ratio...this is totaled between all credit cards) ...It wasn't just the late payment.
And when I built it up, it was because I was managing a higher number of accounts. I was paying off the loans I had taken out. I was establishing a history with the lenders I was going through.
What I want you to take away here is: if they remove the mark on your score, GREAT. THATS WONDERFUL. I'm expecting that they won't, and I'm telling you there's no regulated obligation to do so, let alone care.
But the good news is, it shouldn't be a big deal, at all. It might seem like it, but during 8 years of my THREE back to back late payments, not once was I offered a lower percentage on a loan. Not once did I notice a lower line of credit on a new credit card opening...in fact, companies will frequently offer to increase your credit line because they want you to spend more money. (If your'e responsible with your spending, I encourage you to ALWAYS take this because it helps your credit. Just don't ever, ever spend it...lol) Not once was I denied a loan, or a credit line, or an apartment rental, or entrance to Taco Bell...
The only time this should matter to you is just before getting a new home, or just before getting a new car.
My advice is forget the late payment. Pay your debt down, and let your credit card lines increase naturally (so long as you don't change your spending habits) A month before submitting to qualify for a new loan, pay off as much debt as you can on your current loans, and avoid opening new lines of credit, and you'll do just fine