What does Philemon 1:18 mean?

This verse continues Paul's request of Philemon to treat Onesimus like he would treat Paul. The phrase "has wronged you…or owes you…" offers two key insights. First, Onesimus had likely "wronged" Philemon. He had run away, a serious crime for a bondservant in Roman society. Second, Onesimus likely "owed" Philemon. This may refer to work lost during his absence, or even that Onesimus had stolen from his master when he left, though this is uncertain. Certainly, many entered slavery as a way to pay off debts, another way in which Onesimus might be obligated to Philemon.

And yet, Paul tells Philemon to "charge that to [his] account." Paul personally committed to paying for the debt of Onesimus. As with verse 17, this commitment strengthens the case that Paul wanted Onesimus to be freed. He was even willing to pay the debt for his crimes, to help Onesimus escape slavery. Paul's suggestion was much like the modern day "tab" which needs to be paid at a later date. This was a common practice in that time period.