It’s very common to submit late payments, for any of various types of bills or loans, including mortgage loans. Sometimes people just forget to pay. Sometimes they’re waiting for their next paycheck. Maybe some bills are more lenient on late payments than others, so they’re prioritized lower in the budget.
Whatever the reason, most people assume the only downside to a late payment is an extra fee. That’s not the case. The occasional late payment won’t have any impact, but repeated late payments do show up on your credit report. This will reduce your credit score and make it more difficult to qualify for a loan. If possible, you should make sure to pay bills on time, even for small things like phone bills.