Short answer
Yes, First Credit Services is legit. First Credit Services -- often shortened to FCS -- is a genuine, active third-party collection agency headquartered in Piscataway, New Jersey, and it collects debts on behalf of the creditors and property managers that hire it. It is a real agency, not a scam. Because "First Credit," "First Collection," and "First Financial" are common industry names, the first useful thing you can do is confirm the exact company name and the Piscataway, NJ address on the letter. Then, since FCS is especially active in rental collections, identify whether your balance is a landlord-tenant account -- because that changes how you should respond.
Who they are
First Credit Services is a contingency collection agency: it does not buy debt, it collects it for the company or landlord that originally billed you, and it takes a percentage of whatever it recovers. It runs a distinct rental/landlord-tenant collection program and also handles other consumer accounts such as auto finance, consumer loans, and fitness memberships. Because it works for the original creditor, the written validation you request should name that creditor or property manager clearly -- and it is a good way to confirm you are dealing with the real FCS rather than a similarly named firm or an impostor.
If this is a rental balance: itemize the ledger
Rental debt is rarely a single clean number. It is usually a stack of different charges, and each one has different footing to challenge. Demand a written ledger and separate it into three buckets: unpaid back-rent, property-damage charges, and lease-break or other fees. Back-rent for time you actually lived there is the hardest to dispute; damage charges beyond normal wear and tear, and fees stacked on top, are frequently negotiable or reducible.
Two rules work in your favor. First, your security deposit should be applied and itemized against the balance first -- ask for the deposit accounting. Second, in most states a landlord has a duty to mitigate: if you left early, the landlord must make a reasonable effort to re-rent the unit, which can limit what you owe for the remaining lease term rather than the full balance. Finally, do not confuse an eviction with a money judgment -- an eviction resolves possession of the unit; a money debt has to be separately itemized and proven.
Your rights with an agency
First Credit Services is a debt collector under the federal Fair Debt Collection Practices Act (FDCPA). Within 30 days of first contact, you can demand written validation -- proof of the amount and the name of the creditor or landlord. Until you have that in writing, do not confirm the debt is yours and do not promise to pay: an acknowledgment or a partial payment can restart the statute-of-limitations clock on an old account. If a rental collection appears on your credit file and the numbers are wrong, you can dispute the tradeline with the credit bureaus. And if you are ever sued, do not ignore the summons -- answer on time to preserve your defenses.
Settling a genuinely owed balance
If the account is truly yours and the amount is correct after the itemization and deposit checks above, a genuinely owed, unsecured rental balance is often negotiable. Settle in writing before you send any money, and keep the signed agreement showing the account is resolved and any remaining balance is waived. Remember that if more than $600 of debt is forgiven, you may receive a 1099-C, and the forgiven amount can count as taxable income. Finally, stay alert to impostor red flags: real agencies work through letters and traceable payments -- not gift cards, wire transfers, crypto, threats of arrest, or a refusal to put anything in writing.
This page is general information, not legal or tax advice. Your rights and timelines vary by state; consider consulting a qualified attorney, a nonprofit credit counselor, or legal aid.