Commercial Lease Glossary: 45 Terms Every Tenant Must Know

A large, nationally recognized tenant (e.g., a grocery store or department store) that occupies significant space in a retail center and draws foot traffic that benefits smaller co-tenants. Anchor tenant co-tenancy clauses can give other tenants rent reduction rights or termination options if the anchor leaves.

The transfer of all rights and obligations under a lease from the original tenant (assignor) to a new party (assignee). Unlike subletting, in a full assignment the original tenant typically remains secondarily liable unless the landlord grants a release. Most commercial leases require landlord consent for assignment.

The fixed monthly or annual rent amount stated in the lease, before any additional charges such as CAM, taxes, or insurance. In a gross lease, base rent is the only rent. In a net lease, it's the starting point on top of which operating expenses are added. Also called "minimum rent" in retail percentage leases.

In a modified gross or full-service lease, the base year is the reference year whose operating expenses the landlord absorbs. In subsequent years, tenants pay their proportionate share of increases above the base year amount. A higher base year = fewer tenant pass-throughs; negotiating 2026 as your base year in a 2026 lease is standard.

The physical improvements made to a space to suit a tenant's needs. Buildouts can be landlord-performed (turnkey), tenant-managed with a tenant improvement allowance, or tenant-performed at tenant's own cost. The scope, timeline, and ownership of improvements should be clearly defined in the lease.

Charges passed through from landlord to tenants to cover the cost of maintaining shared spaces — lobbies, parking lots, landscaping, hallways, and building systems. CAM is one of the most negotiated items in a commercial lease. Always ask for an expense cap (e.g., 5% annual increase) and audit rights.

A valuation metric equal to Net Operating Income divided by property value. Relevant to tenants primarily when evaluating whether a landlord's asking rent is market-rate, and to investors assessing the income a property generates relative to its value.

A lease provision giving a tenant rent reduction or termination rights if key co-tenants (especially anchor tenants in retail) vacate or if occupancy falls below a threshold. Essential for retail tenants whose business depends on neighboring foot traffic.

The date on which the lease term officially begins. In some leases, this is a fixed calendar date. In others (especially build-to-suit or extensive renovation situations), it's tied to a "substantial completion" milestone. The rent start date may differ from the commencement date — free rent periods are common.

A government-published measure of inflation used in many rent escalation clauses. A CPI-based escalation means rent increases each year by the percentage change in CPI, subject to a floor (e.g., 2%) and ceiling (e.g., 5%). CPI escalations can be unpredictable; fixed-rate escalations are often easier to budget.

The time a defaulting party has to correct a lease violation before the other party can exercise remedies (including termination). Non-payment defaults typically have a 3–10 day cure period. Non-monetary defaults (e.g., unauthorized alterations) may have 30–60 days, sometimes with a right to continue curing if diligently pursued.

A failure by either party to fulfill an obligation under the lease. Tenant defaults commonly include non-payment of rent, unauthorized use of the premises, abandonment, or insolvency. Landlord defaults include failure to maintain premises or provide agreed services. Default clauses define rights, remedies, and the required cure period.

A landlord-friendly clause allowing the landlord to terminate the lease with notice (often 6–18 months) if the building is to be demolished or substantially redeveloped. Particularly risky for tenants who have invested heavily in buildout or who rely on location-specific operations. Always try to negotiate this out or require substantial notice with relocation assistance.

A signed document in which a tenant confirms key facts about the lease — current rent, lease term, absence of known defaults, and the status of any tenant concessions. Landlords require estoppel certificates when selling or refinancing a property. As a tenant, read estoppels carefully — signing an inaccurate one can waive your rights.

A provision prohibiting the landlord from leasing space in the same development to a direct competitor of the tenant. Critical for retail tenants and anchor operators. Scope matters enormously — a bakery's exclusivity should extend to "retail bakery sales," not just "bakeries," to prevent a café from encroaching.

A right (but not an obligation) for the tenant to lease additional space — typically adjacent — at a predetermined or market rent within a specified window. Expansion options are valuable for growing businesses but require careful drafting to specify which space, timing, pricing, and whether they expire if not exercised.

A clause excusing a party from performance when extraordinary, unforeseeable events — hurricanes, pandemics, government orders — make performance impossible or impractical. Post-2020, tenants should ensure force majeure applies to rent obligations, not just timelines. Landlords typically resist this.

A period at lease commencement during which the tenant pays no base rent, typically used to allow time for buildout and business setup. Free rent is a common concession in soft markets. Note: CAM and operating expenses may still be due during a free rent period unless specifically excluded.

A lease structure in which the tenant pays a fixed rent that includes all or most operating costs — taxes, insurance, maintenance. The landlord covers building operating expenses. Common in office buildings. Simpler for tenants but base rents are typically higher to compensate the landlord for operating risk.

When a tenant remains in the premises after the lease term expires without executing a new lease. Most leases impose a holdover penalty — rent at 125–200% of the last month's rate. Some leases convert to month-to-month; others allow the landlord to treat the holdover as an unlawful detainer. Always address holdover exposure well before lease expiration.

Lease provisions specifying the types and minimum amounts of insurance the tenant must carry — general liability, property, workers' compensation, and sometimes umbrella/excess coverage. Landlords require to be named as additional insured. Review carefully: minimum amounts (often $2M–$5M for general liability) must match your broker's advice for your industry and lease size.

A non-binding document outlining the key terms of a proposed lease before a formal agreement is drafted. LOIs typically cover rent, term, tenant improvement allowance, options, and exclusivity. Though non-binding, the LOI sets expectations that are difficult to walk back in full lease negotiations — treat it seriously.

A summary document that distills a full lease into its essential terms — parties, dates, rent, CAM, options, and critical clauses — for quick reference. Property managers and asset managers use lease abstracts to manage large portfolios without rereading full documents. AI tools like LeaseAI generate lease abstracts automatically from any PDF.

The main commercial lease types: Gross Lease (tenant pays fixed rent; landlord covers ops), Net Lease (tenant pays base rent + some/all ops), Double Net (NN) (tenant pays rent + taxes + insurance), Triple Net (NNN) (tenant pays rent + taxes + insurance + maintenance), Modified Gross (shared costs, negotiated split), Percentage Lease (base rent + % of sales, common in retail).

The prevailing rent for comparable space in the same market. Critical when exercising a renewal option at "fair market rent" — the definition of fair market rent, and the process for determining it (appraisal, arbitration, or landlord offer + tenant acceptance), must be clearly spelled out in the lease to avoid disputes.

A hybrid lease structure where certain operating costs are shared between landlord and tenant — often with the tenant paying base rent plus some specified expenses (e.g., electricity), while the landlord covers others. The specific split is negotiated. More common in multi-tenant office buildings than industrial or retail.

The most landlord-favorable lease structure — the tenant pays base rent plus all three "nets": property taxes, building insurance, and maintenance/repairs. NNN leases are standard for freestanding retail (fast food, dollar stores) and single-tenant industrial. Because tenants bear operating risk, base rents in NNN leases are typically lower than gross equivalents.

A Subordination, Non-Disturbance, and Attornment agreement. Subordination means the tenant's lease is junior to the lender's mortgage. Non-disturbance means the lender won't evict the tenant if it forecloses (so long as the tenant isn't in default). Attornment means the tenant agrees to recognize a new owner. Critical protection for tenants in leveraged buildings.

All costs associated with operating and maintaining a building — utilities, cleaning, repairs, management fees, landscaping, security, property taxes, and insurance. In net leases, these are passed through to tenants pro-rata. Always request an itemized operating expense statement and confirm which costs are excluded (capital improvements typically should be excluded from tenant pass-throughs).

A tenant's contractual right to extend the lease for an additional term, typically at a stated rate or "fair market rent." Options must be exercised within a strict notice window (often 6–12 months before expiration). Missing the window is one of the most common and costly commercial tenant mistakes — a calendared reminder is essential.

A provision making an individual (often a business owner or principal) personally liable for lease obligations, even if the tenant entity defaults or goes bankrupt. Common for small business tenants and startups. Try to negotiate a "good guy" clause (personal liability ends when tenant vacates and surrenders possession) or limit the guarantee to a specific dollar amount or time period.

The clause defining what business activities the tenant may conduct on the premises. Should be drafted broadly enough to accommodate your evolving business needs. A tenant whose permitted use clause limits them to "retail shoe sales" may face landlord objections to adding accessories, bags, or apparel lines.

A tenant's proportionate share of operating expenses and CAM, calculated as the tenant's leased square footage divided by the building's total rentable area. Example: a 5,000 sq ft tenant in a 50,000 sq ft building has a 10% pro-rata share. Always verify the denominator — "gross leasable area" vs. "rentable area" can significantly affect your share.

A landlord right to "recapture" (take back) the premises if a tenant requests permission to sublease or assign. If the landlord exercises recapture, the original lease terminates and the landlord is free to lease directly to the proposed subtenant at market rates. Gives landlords an effective veto on subleasing — try to negotiate it out or limit the recapture period.

A temporary reduction or elimination of rent, typically in response to the premises becoming unusable (fire damage, casualty) or as a lease concession. Landlords may grant abatement during buildout periods. In casualty events, the threshold for abatement (e.g., "more than 25% of the premises unusable") and the restoration timeline are key negotiation points.

Scheduled increases in base rent over the lease term. Common structures: (1) Fixed annual increase (e.g., 3%/year), (2) CPI-indexed increases, (3) Step rents (fixed jumps at set dates). Fixed escalations are predictable; CPI-indexed escalations can accelerate in high-inflation periods. Uncapped CPI escalations are a significant risk.

A right requiring the landlord to offer the tenant a specific space (often adjacent) before marketing it to third parties. The tenant has a set time to accept or decline. Weaker than a right of first refusal — the tenant gets the first offer, not the right to match a competing offer.

A right allowing the tenant to match any third-party offer the landlord accepts on a specific space. Stronger than ROFO but operationally tricky — the landlord must first negotiate with a third party and then offer the tenant the chance to match those exact terms. Can slow down the landlord's leasing process significantly.

Cash (or a letter of credit) held by the landlord as security against tenant default. Typically 1–3 months of base rent for creditworthy tenants; more for startups or weak credits. Negotiate: step-down provisions that reduce the deposit after 12–24 months of on-time payment, and the conditions under which it must be returned (usually within 30 days of lease expiration).

An arrangement in which the original tenant (sublandlord) rents some or all of the leased space to a third party (subtenant) while remaining responsible to the landlord under the original lease. Unlike assignment, the original tenant retains privity with the landlord. Subleases typically require landlord consent and are often prohibited or restricted.

A landlord contribution toward tenant buildout costs, typically expressed as $/sq ft. Market TI for class A office in major markets ranges from $80–$150/sq ft. Unused TI may or may not be repurposable as rent credit — check the lease. TI is usually advanced on a reimbursement basis with landlord approval of plans and invoices.

A commercial real estate broker who exclusively represents the tenant's interests in a lease negotiation. Tenant reps are typically paid by the landlord (from the commission the listing broker would otherwise receive entirely). Using a tenant rep costs the tenant nothing and significantly improves negotiating leverage — always use one.

A tenant's contractual right to end the lease before expiration upon giving specified notice and paying a termination fee (typically the landlord's unamortized TI + leasing commissions + 1–6 months of rent). Often exercisable only at specific dates (e.g., end of year 3 in a 5-year lease). Critical for businesses facing uncertain growth.

Usable square footage is the space the tenant actually occupies. Rentable square footage adds a pro-rata share of common areas (lobbies, corridors, restrooms, mechanical rooms). The ratio of rentable to usable is the "load factor" or "loss factor" — typically 10–20% in office buildings. You pay rent on rentable area, not usable. Always verify the load factor before signing.

See Permitted Use above. The use clause and exclusive use clause work together — the use clause defines what you can do; the exclusivity clause prevents competitors from doing the same nearby.

An exhibit to the lease specifying the buildout scope, quality standards, responsibilities, timeline, and budget. Workletters define what the landlord will build (landlord work), what the tenant will build (tenant work), and the TI allowance process. A vague workletter is a major risk — require detailed specifications, not just allowances.