NYC residential sales linked to ACRIS deeds and mortgages, 2016–2025

New York City publishes its property sales and its recorded deeds and mortgages as separate open datasets that do not join directly. Condominiums are the hardest case: the Department of Finance's parcel identifier for a unit sale is usually the building's billing lot, while ACRIS records the deed and mortgage under the unit's own lot. This dataset makes the join once, with fixed and documented rules. It covers all 729,047 one- to three-family house, condominium and co-operative sales recorded by the Department of Finance in 2016–2025. For houses and condominiums in the four boroughs ACRIS covers, each sale carries its matched deed, whether it was financed (in three windows), the loan amount and ACRIS document identifiers. Each linked deed also carries flags for company buyers, same-surname transfers, shared mailing addresses and lender take-title events whose recorded amount can follow a legal rule rather than a price. No party names are included. The linkage reproduces the archived panels of the companion papers. Financing flags agree for every house and for all but 4 of 82,348 compared condominiums, and the rebuilt condominium loans reproduce the 1.28% average mortgage-recording-tax burden reported in The Shape of the Tax, which its own deposit could not recreate. The package contains the three linked tables, a codebook, the raw extracts with their retrieval manifests, and standard-library Python scripts that rebuild everything from NYC Open Data. Companion papers: Who Gets the House? (doi:10.5281/zenodo.22421850), The Shape of the Tax (doi:10.5281/zenodo.22925301) and When a Deed Is Not a Market Sale (doi:10.5281/zenodo.22925383).