Filing deadline

No recorded claim of lien exists. The lien is perfected only by court attachment: the claimant sues (breach of contract) and petitions ex parte for an attachment to secure the mechanic's lien, swearing to the contract, the unpaid amount, furnishing within the past 120 days, a reasonable land description, and (for subs) the owner notice. The granted petition plus a Writ of Attachment must then be recorded in the registry of deeds no later than 120 consecutive days (not 4 months) after the claimant's last contract-required furnishing (warranty/remedial work doesn't count; open-account suppliers with a full-needs contract measure from last delivery; multi-lot single contracts run from the last furnishing on any lot).

Notice prerequisites

No filing is required before work, and no notice is strictly mandatory - but a subcontractor/supplier who skips the written Notice of Intent to Lien to the owner has its lien capped at whatever the owner still owes the prime when the lien action starts. Serving the notice before starting work fully protects the lien amount; serving it later caps the lien at the prime-contract balance as of receipt (later owner backcharges can wipe it out entirely). After noticing, the sub should send the owner updated Statements of Account at least every 30 days, or the lien is frozen at the last stated amount.

Service on the owner

The attachment issues ex parte, so the owner is served with the suit papers and attachment afterward and may demand a prompt hearing (typically within two weeks) to contest timeliness, description, sub's notice, amount, or waiver. On lender-posted jobsites, lien claimants should notify the construction lender within 15 days of the posting that they are furnishing labor/materials, though omission alone does not void the lien.

Enforcement

Suit and perfection are the same act, so the effective deadline to sue is the same 120 days from last furnishing. The attachment then secures the eventual contract judgment, satisfied by set-off of the real estate or sheriff's sale; no separate lis pendens step is described.

N.H. RSA ch. 447 (esp. 447:2, 447:5-447:12-b, 447:14-16); RSA 511, 511-A (attachment); RSA 529