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Portsmouth is one of New Hampshire's most densely populated and historically significant cities, situated along the Piscataqua River in Rockingham County. The city's vibrant downtown and proximity to the seacoast make it a competitive rental market, with a significant share of residents renting rather than owning their homes. Renters in Portsmouth frequently ask about rent increases, security deposit rules, and what steps a landlord must take before pursuing eviction.
Tenant rights in Portsmouth are governed entirely by New Hampshire state law — primarily RSA Chapter 540 (Actions Against Tenants) and RSA Chapter 540-A (Prohibited Practices). Portsmouth has not enacted any local rent control ordinance, tenant relocation assistance program, or just-cause eviction requirement beyond what the state mandates. This means that understanding your rights requires a solid grasp of state statutes, which this guide provides.
This page is intended as an informational resource only and does not constitute legal advice. Statutes can change, and individual situations vary. If you are facing eviction or a serious housing dispute, please contact a qualified attorney or free legal aid provider such as New Hampshire Legal Assistance.
Portsmouth has no rent control, and New Hampshire state law does not provide for it. Unlike some states that actively preempt rent control through a single preemption statute, New Hampshire simply has no enabling legislation that would allow a municipality to cap rents, and no city in the state — including Portsmouth — has ever enacted a rent stabilization ordinance. The governing framework for landlord-tenant relations is RSA Chapter 540, which addresses notices, evictions, and remedies, but contains no rent-stabilization provisions.
In practice, this means a Portsmouth landlord may raise your rent by any amount, at any time, provided they give you the legally required notice. For a month-to-month tenancy, that means at least 30 days' written notice before the rent increase takes effect, consistent with RSA 540:2's notice requirement for changes to tenancy terms. For fixed-term leases, the rent is set in the lease and cannot be increased until the lease expires. There is no formula, no percentage cap, and no local board or agency that reviews proposed rent increases in Portsmouth.
Renters concerned about large rent increases should review their lease carefully, document all written communications with their landlord, and consult New Hampshire Legal Assistance (nhla.org) if they believe a rent increase is being used as a form of retaliation in violation of RSA 540:13-a.
New Hampshire's landlord-tenant statutes provide several core protections that apply to every renter in Portsmouth. Below are the most important protections and their statutory sources.
Implied Warranty of Habitability: New Hampshire recognizes an implied warranty of habitability through common law and municipal housing codes. Landlords are legally required to maintain rental units in a safe and livable condition, including functioning heat, plumbing, and structural integrity. If your landlord fails to address serious habitability issues, you may contact Portsmouth's Code Enforcement Division to trigger a municipal inspection. While RSA 540 does not enumerate specific repair timelines, persistent code violations can form a basis for legal action.
Security Deposit Rules (RSA 540-A:5 & 540-A:6): Landlords may not collect a security deposit exceeding one month's rent or $100, whichever is greater. Deposits must be held in a separate account and returned within 30 days of move-out, accompanied by an itemized written statement of any deductions. Wrongful withholding entitles the tenant to double the withheld amount as damages.
Notice Requirements (RSA 540:2): For month-to-month tenancies, landlords must provide at least 30 days' written notice to terminate the tenancy or make a material change such as a rent increase. Week-to-week tenancies require 7 days' written notice. Fixed-term lease tenants are not subject to mid-lease termination without cause, absent a lease provision permitting it.
Anti-Retaliation Protection (RSA 540:13-a): A landlord may not evict, raise rent, reduce services, or otherwise retaliate against a tenant for reporting housing code violations, contacting a government agency, or exercising any legal right under state law. A tenant who proves retaliation may assert it as a defense in eviction proceedings and may be entitled to damages.
Prohibition on Self-Help Eviction (RSA 540-A:2 & 540-A:3): It is unlawful for a landlord to evict a tenant by any means other than the court process established under RSA Chapter 540. Specifically, a landlord may not change the locks, remove doors or windows, shut off utilities, or remove the tenant's personal property to force them out. Violations of RSA 540-A are subject to civil damages of up to $1,000 per violation plus attorney's fees under RSA 540-A:4.
New Hampshire's security deposit law is found in RSA Chapter 540-A and provides the following specific rules for Portsmouth landlords and tenants:
Cap on Amount (RSA 540-A:6, I): A landlord may not require a security deposit greater than one month's rent or $100, whichever is greater. For example, if your monthly rent is $1,800, the maximum security deposit is $1,800. If your monthly rent is $75, the maximum deposit is $100.
Separate Account Requirement (RSA 540-A:5): Landlords must hold security deposits in a separate bank account and may not commingle them with other funds. Upon request, a landlord must provide the tenant with the name and address of the bank and the account number where the deposit is held.
Return Deadline (RSA 540-A:6, II): The landlord must return the security deposit — along with a written, itemized statement of any lawful deductions — within 30 days after the tenancy ends and you return possession of the unit. Deductions are permitted only for unpaid rent and damages beyond normal wear and tear.
Penalty for Wrongful Withholding (RSA 540-A:6, III): If a landlord fails to return the deposit or provide an itemized statement within 30 days, or wrongfully withholds any portion, the tenant is entitled to recover double the amount wrongfully withheld, plus reasonable attorney's fees, through a civil action in New Hampshire District Court. To protect your rights, document the condition of the unit with dated photos at both move-in and move-out, and provide your landlord with a forwarding address in writing.
Evictions in Portsmouth follow the process established under RSA Chapter 540. New Hampshire does not require just cause for eviction — a landlord may choose not to renew a tenancy for any non-retaliatory reason. However, every eviction must proceed through the court; a landlord who bypasses this process violates RSA 540-A:2.
Step 1 — Written Notice: Before filing for eviction, a landlord must serve the tenant with written notice. The required notice period depends on the reason for eviction: (a) Nonpayment of rent: 7 days' written notice to pay or vacate (RSA 540:3); (b) Lease violation other than nonpayment: 30 days' written notice to cure or vacate (RSA 540:2); (c) No-cause termination of a month-to-month tenancy: 30 days' written notice (RSA 540:2); (d) Week-to-week tenancy: 7 days' written notice (RSA 540:2).
Step 2 — Filing a Writ of Summons: If the tenant does not vacate after proper notice, the landlord must file a Landlord and Tenant Writ in New Hampshire Circuit Court — District Division. The tenant is then served with a summons and given the opportunity to respond. Filing fees and service requirements are governed by the New Hampshire Circuit Court rules.
Step 3 — Court Hearing: Both parties appear before a judge. Tenants may raise defenses including improper notice, retaliation (RSA 540:13-a), habitability issues, or failure to comply with security deposit law. If the landlord prevails, the court issues a judgment for possession.
Step 4 — Writ of Possession: After judgment, the landlord may obtain a Writ of Possession, which authorizes a sheriff or constable to physically remove the tenant if they have not vacated. Only a law enforcement officer acting under a court order may carry out the removal.
Self-Help Eviction is Illegal (RSA 540-A:2 & 540-A:3): At no point in this process may a landlord lock out the tenant, remove their belongings, shut off heat, water, or electricity, or otherwise interfere with the tenant's peaceful possession of the unit. Such actions expose the landlord to civil liability of up to $1,000 per violation plus attorney's fees under RSA 540-A:4. If your landlord attempts a self-help eviction, contact New Hampshire Legal Assistance or local law enforcement immediately.
This page is provided for informational purposes only and does not constitute legal advice. Tenant rights laws in New Hampshire and Portsmouth may change, and individual circumstances vary. The information on this page reflects our best understanding of New Hampshire statutes as of April 2026 but may not reflect recent legislative changes or court decisions. If you are facing eviction, a security deposit dispute, or any serious housing matter, you should consult a qualified attorney or contact New Hampshire Legal Assistance (nhla.org) for guidance specific to your situation. RentCheckMe is not a law firm and does not provide legal representation.
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