Fees & public finance
Will-serve letter
A utility's written commitment that capacity exists and it will serve a project — the assurance lenders and map approvals routinely require.
Definition
A will-serve letter is a utility's written statement that it has capacity for, and will provide service to, a specific project — typically listing conditions: capacity payments, offsite improvements, and an expiration date. Water and sewer will-serves are the lender staples; for large residential subdivisions the requirement hardens into statute, since the Subdivision Map Act (Gov. Code § 66473.7) conditions tentative-map approval for projects of more than 500 units on a written verification of sufficient water supply, alongside the SB 610 water-supply assessments that ride CEQA review.
Why it matters in an underwrite
Construction lenders condition closing on current will-serve letters, and the letters expire — a stale one resurfaces at the worst moment, sometimes after a district has imposed a connection moratorium or drought restriction that changes the answer. Get the letters early, calendar their expirations against the construction-loan closing, and price their conditions: the offsite main or capacity payment buried in a will-serve is a budget line, not a formality.
Sources & related guides
See also
See the term in the law itself
Read the controlling text in the Code Library, or ask the AI how it applies to your project.
Last reviewed 2026-07-29. General information, not legal advice.