Glossary

The NYC housing terms
everyone assumes you know.

AMI, DTI, flip tax, post-closing liquidity: the shorthand that shows up in every listing, board package, and closing statement. Every term here comes with a worked example and a named source, and links straight into the calculator that runs the math for you.

Renting

40x Rule

The NYC rental-market convention that a tenant's annual income should be at least 40 times the monthly rent.

Broker Fee

A commission paid to a real estate broker for help renting an apartment. Under NYC's FARE Act (effective June 11, 2025), a tenant generally pays only a broker the tenant chose to hire; a landlord's or listing agent's fee can't be passed on.

FARE Act

NYC law (effective June 11, 2025) making whoever hires a broker responsible for paying that broker's fee, usually the landlord, not the tenant.

Guarantor

A co-signer who agrees to cover rent if the tenant can't. NYC landlords typically require a guarantor's income to be about 80x the monthly rent.

Key Money

An illegal upfront cash payment a landlord, super, or agent demands just to hand over the keys or an application, separate from any legal fee and not recoverable if paid.

Net Effective Rent

The average monthly rent over a lease after a concession like a free month is spread across the term. It's lower than the gross rent you'll actually pay in the non-free months, and renewals are typically priced off the gross rent.

Preferential Rent

A rent on a rent-stabilized apartment that's lower than the legal regulated rent the landlord could charge. Since 2019, renewal increases are generally calculated on the preferential rent, not the higher legal one.

Renewal Lease

A new lease term for a tenant already living in the apartment. Rent-stabilized tenants generally have a right to one; market-rate tenants generally don't, though state law requires notice before big increases or a non-renewal.

Rent Guidelines Board (RGB)

The nine-member, mayor-appointed NYC board that votes each year on the maximum rent increases for rent-stabilized lease renewals. Its current order freezes renewals at 0% for leases starting October 1, 2026 through September 30, 2027.

Rent Stabilization

NYC's rent regulation system covering roughly one million apartments, where annual lease renewal increases are capped by a citywide board rather than set by the landlord.

Security Deposit

Money a landlord holds against unpaid rent or damage beyond normal wear and tear. In New York it's generally capped at one month's rent and must come back, minus itemized deductions, within 14 days of move-out.

Buying

Common Charges

The monthly fee a condo owner pays for building upkeep and shared amenities; the condo equivalent of a co-op's maintenance, but without the underlying mortgage or property tax bundled in.

Contract of Sale

The written purchase agreement that makes a NYC deal binding. An accepted offer isn't; the deal only becomes enforceable once both sides sign the attorney-negotiated contract and the buyer puts down a deposit, customarily 10%.

Escrow Account (Property Tax and Insurance)

An account your mortgage servicer runs to pay property taxes and certain insurance bills for you, funded by an extra amount added to each monthly mortgage payment.

Good Faith Deposit

The customary 10% of purchase price a NYC buyer wires into attorney escrow when signing the contract of sale; separate from, but later applied toward, the down payment.

Mortgage Points (Discount Points)

An upfront fee paid at closing to buy a lower interest rate. One point equals 1% of the loan amount.

Offering Plan

The disclosure document a sponsor must file with the New York Attorney General before selling co-op shares or condo units, laying out prices, projected monthly costs, the building's budget, and the governing documents.

Private Mortgage Insurance (PMI)

Insurance that protects the lender, not you, on a conventional loan with less than 20% down. It's added to your monthly payment and can be cancelled once you build enough equity.

Rate Lock

A lender's commitment that your interest rate won't change between the offer and closing, as long as you close within the lock period and your application doesn't change.

Title Insurance

A one-time policy bought at closing that covers claims against a property's ownership from before the purchase. Lenders require a lender's policy; the owner's policy protects the buyer. In New York, premiums come from a state-approved rate manual.

Working Capital Contribution

A one-time payment a buyer makes at closing into a building's working capital fund, usually expressed as a number of months of common charges. Most common at new-development condos.

Co-ops

Board Package

The application dossier a NYC co-op buyer submits for board approval: financials, references, and personal statements, reviewed after mortgage approval is already in hand.

Co-op Sublet Policy

The building-specific rules governing whether and how long a shareholder can rent out their unit, commonly capped at two years in a five-year window, with board approval and a surcharge.

Flip Tax

A resale fee a co-op corporation charges when shares change hands, typically 1-3% of sale price and seller-paid. Not a government tax.

Maintenance (Co-op)

The monthly fee co-op shareholders pay that bundles building upkeep, a share of the building's underlying mortgage, and a share of its property taxes into one number.

Post-Closing Liquidity

The liquid cash a co-op board requires you to have left over after paying the down payment and closing costs, typically 12+ months of maintenance and mortgage.

Proprietary Lease

The lease a co-op corporation gives each shareholder that grants the right to occupy a specific apartment. Paired with the stock certificate, it's what you actually get when you "buy" a co-op.

Special Assessment

A temporary extra charge a co-op or condo board levies on owners to pay for something the regular budget doesn't cover, usually a big repair. In a co-op it's typically split by shares and billed alongside maintenance.

Sponsor Unit

A co-op apartment still owned by the building's original conversion sponsor rather than an individual shareholder, sold without board approval, often with easier financing.

Underlying Mortgage

A loan the co-op corporation itself takes out against the building. Shareholders pay it off collectively through their monthly maintenance, in proportion to their shares.

Taxes

485-x Tax Abatement

The property tax exemption for new residential construction that replaced 421-a in 2024, offering up to 40 years of tax relief in exchange for permanently affordable units.

CEMA (Consolidation, Extension and Modification Agreement)

A New York mortgage structure that keeps an existing, already-taxed mortgage alive and consolidates it with any new borrowing, so mortgage recording tax is owed only on the new money.

FICA Tax

The combined 7.65% payroll tax (6.2% Social Security + 1.45% Medicare) withheld from every paycheck, plus a 0.9% Additional Medicare surtax above set income thresholds.

Mansion Tax

A NY State buyer-paid tax starting at 1% of full purchase price on residential sales of $1,000,000 or more, stepping up to 3.9% above $25 million.

Mortgage Recording Tax (MRT)

A NYC/NYS tax on financed real property purchases (about 1.80% of the loan under $500,000, 1.925% at or above) that applies to condos but not co-ops.

NYC Local Income Tax (NYC Resident Tax)

A city income tax NYC residents pay on top of NY State tax (four brackets from 3.078% to 3.876%) that nonresidents who merely work in the city do not owe.

NYC Real Property Transfer Tax (RPTT)

New York City's tax on property sales over $25,000: 1% of the price at or under $500,000 and 1.425% above that for homes, condos, and co-ops. The seller generally pays it.

NYS Real Estate Transfer Tax

New York State's transfer tax on property sales: 0.4% of the price ($2 per $500), plus a 0.25% "additional base tax" on NYC residential sales of $3 million or more. The seller generally pays it.

STAR Exemption

A New York State property tax break for a primary residence (Basic STAR for most owners, Enhanced STAR for seniors 65+ under an income limit) that reduces the school-tax portion of the bill.

Run your own numbers

Every term here feeds into one of our calculators. Once you understand the rule, see exactly how it affects your max price or affordable rent.