noun
written estimate; written quotation
A document stating an estimated cost, often used in business or construction contexts.
工事の前に、業者から積り書をもらった。
Before the construction, I received a written estimate from the contractor.
見積書 is a more common and formal term for a written estimate or quotation, while 積り書 is less frequent and may sound slightly older or more informal.
Compound of 積もり (estimate) and 書き (writing). The exact historical derivation is uncertain.