Discovering that you accidentally missed a payment due date on a credit card or loan can be an unsettling feeling.

Your lender might charge you a late fee for the oversight and even worse, it may negatively affect your credit scores.

Here's the good news: Your payment has to be a full 30 days late before a lender can report it to the credit bureaus. Once your payment passes the 30-day late mark, all bets are off and damage to your credit becomes a very real possibility.

There's no question that the payment history on your credit reports is important. In FICO brand scoring models, payment history is worth 35 percent of your credit score.

Yet a late payment, or any other negative blemish on your credit reports, isn't worth a specific number of points. You won't, for example, automatically lose 15 points from your score when a 30-day late payment is added to your report. (FICO scores range from 300 to 850.) The credit scoring process is more complicated.

When it comes to credit scores, you don't have just one. Rather, there are hundreds of different credit scores available for lenders to choose from. Score providers include industry leader FICO as well as VantageScore, which was created by the three major credit-reporting agencies, and smaller boutique shops. It's up to each lender to decide which brand and version of a scoring model it will purchase and use to evaluate the credit reports of new credit applicants.

Which credit score version a lender uses can make a big difference in how much a 30-day late payment will affect your score. In older FICO scoring models, such as the ones still used by the mortgage industry, even an isolated 30-day late payment could potentially have a very negative impact on your credit scores.

With the newer FICO 8 scoring model, if a 30-day late payment is the only one appearing on your credit reports, the effect on your scores will not be as severe.

Here's the catch: You won't know which model or version of a credit score a lender is going to use before you apply for financing.

The number of points you may see shaved off your score when a late payment is added to your credit reports can depend upon other factors as well. FICO scoring models will consider the severity of the late payment, how recently it occurred, and how frequently you have paid late.

How long do late payments remain on your credit reports?

The Fair Credit Reporting Act (FCRA) limits late payments on your credit reports to a seven-year maximum shelf life. After that, they must be deleted from your credit

Michelle Black writes for Bankrate.com.