Short answer
Your bill becomes past due and builds interest and penalties each month. If it is unpaid by December 31 and you have no payment plan, the account is delinquent on January 1. The City can then file a lien, add legal fees and start the process toward a sheriff sale.
Past due first
The City of Philadelphia says that when you miss the payment deadline, the bill becomes past due and builds monthly interest and penalties. You may get bills from the Department of Revenue and from a collection agency. This is the stage where acting early costs the least. The most expensive moment is the one you ignore. Penalties and interest stack month after month, and once the account is delinquent the City can add legal fees. That is why even a small balance can grow into a serious one over a year or two. If you cannot pay in full, a plan is almost always better than silence. The City says enrolling in a plan makes your account compliant and protects the property from sheriff sale.
Delinquent on January 1
If you have not paid or enrolled in a payment plan by December 31, the account becomes delinquent on January 1 of the following year. The City can then put a lien on the property and add legal fees to the account, which increases the debt. A lien is a legal claim against the property because of the debt owed.
Sheriff sale
The City says a lien is the start of the foreclosure process, and the property can eventually be sold at a sheriff sale, a public auction to collect unpaid real estate taxes. The City also says that enrolling in a payment agreement means your account is compliant and your property is safe from sheriff sale.
Steps to take now
Pull out your latest tax bill and note the due date and the balance. Call or visit the City's Department of Revenue, and ask what you owe, including interest and penalties. Ask whether an Owner-Occupied Payment Agreement or an installment plan fits your situation, and what income information you must provide. Do not ignore letters from the City or a collection agency. If you plan to sell, ask the City for a current balance so the title company can include it in the payoff. If you want to keep the house, enrolling in a plan before the account becomes delinquent can keep costs from growing. Keep every receipt.
Help that exists
The City offers an Owner-Occupied Payment Agreement, called OOPA, for owners who live in their homes with delinquent real estate taxes. The City says there is no down payment required and applicants disclose income and household information. Installment plans are available too. These are worth checking before you decide to sell. If you do want to sell, Kaizen Home Buyers can make an as-is cash offer within 24 hours, with no repairs and no agent commission, and close in 14 to 30 days or on your date. Call 267-329-0084.