Over a span of 5 years I have not been late on any of my student loan payments. This past month I moved and the letter was sent to me after the date in which it was due. All said and done, I sent in the payment a week after it was due. Will this affect my credit?
In general, how late is late for it to affect your credit? Is it only when they report you to a collection agency?
You are almost certainly in the clear. Payment would need to be +30 days late in order to get a derogatory remark on your payment history. In all honesty, you should simply call up the servicer's CSR and tell them payment has been sent. Watch your account and make sure it was received. Some servicers do not even report 30 day lates and wait until the account is +60 to start reporting derogs.