Default Interest & Late Fees in New Hampshire Commercial Leases

The residential 15-day grace period mandated by RSA 540-A:8 does not apply to commercial leases in New Hampshire. Commercial landlords have full contractual freedom to define when late fees begin accruing and how large they are.

Because there is no prevailing statute, commercial late fees are governed entirely by the lease agreement and common-law contract principles.

Disclaimer: This guide provides general legal information for educational purposes only and does not constitute legal advice. Always consult a licensed commercial real estate attorney. Information last verified: March 2026.

No Grace Period Required

Unlike residential tenants, commercial tenants in New Hampshire are not entitled to a 15-day grace period. A commercial lease can legally stipulate that a late fee applies on the very next business day after the rent is due.

Most commercial leases do include a short contractual grace period (typically 3 to 5 business days) as a matter of commercial practicality, but this is a negotiated term, not a statutory right.

Structuring Enforceable Late Fees

1. Flat Late Fees

A fixed dollar amount (e.g., $500) or a percentage of the monthly base rent (e.g., 5%) assessed after the contractual grace period expires. To survive judicial scrutiny, this must be a reasonable pre-estimate of the landlord's administrative loss, not an unconscionable penalty.

2. Default Interest

The most powerful tool in a commercial landlord's arsenal. The lease dictates a high interest rate on all unpaid balances:

• Example: "Any rent or other sums not paid within five (5) days of the due date shall bear interest at 12% per annum, calculated daily from the original due date until paid in full."
• New Hampshire courts generally accept commercially reasonable default interest rates (typically 10% to 18% per annum) as enforceable liquidated damages.

3. Administrative Recovery Fees

The lease may require the tenant to reimburse the landlord for all out-of-pocket costs incurred in pursuing the debt, including legal fees, collection agency costs, and court filing fees.

Defining Late Fees as "Additional Rent"

A critical legal maneuver: explicitly defining unpaid late fees, default interest, and NNN outgoings as "Additional Rent" in the lease. This allows the landlord to treat non-payment of these charges as a rent default, enabling the faster eviction timeline rather than a slower breach-of-contract proceeding.

Automating Complex Arrears

Calculating compounding daily interest on a commercial tenant who is 22 days late on base rent but current on their NNN charges requires precision accounting. Landager automates these complex commercial ledgers, applying pre-configured default interest rules exactly on the contracted trigger date and generating mathematically flawless, lease-compliant demand notices without manual error.

Back to New Hampshire Commercial Landlord-Tenant Laws Overview.