{"id":1132,"date":"2024-03-11T20:36:21","date_gmt":"2024-03-11T20:36:21","guid":{"rendered":"https:\/\/lesswing.com\/?p=1132"},"modified":"2024-03-12T21:38:46","modified_gmt":"2024-03-12T21:38:46","slug":"is-it-a-property-or-a-parcel","status":"publish","type":"post","link":"https:\/\/lesswing.com\/index.php\/2024\/03\/11\/is-it-a-property-or-a-parcel\/","title":{"rendered":"Is it a Property or a Parcel?"},"content":{"rendered":"\n<p>Consumers refer to properties using an address but when buying and selling, what changes hands is called a parcel. <strong>Counties record parcel transfers to protect owners&#8217; real property rights<\/strong>.  Parcels pre-date the postal system.  Record keeping is performed at the parcel level because it is possible to sell real estate that does not have a postal address.  An example would be a deeded parking space that accompanies the second-floor flat.  Two parcels are part of the offer, but the consumer associates the flat and parking part with the address.<\/p>\n\n\n\n<p>Local governments use parcel identifiers to record deeds, process liens and issue tax assessments. <strong>The format of parcel identifiers varies by location and identical identifiers can be used in multiple locations. <\/strong>Searching across locations with a parcel identifier is challenging because the identifiers are not guaranteed to be unique. This results in the user needing to select the parcel they are interested in from a list of parcels with the same identifier.  Computer-to-computer systems that move information through business processes are not well-suited for conversations like this.  Earlier real estate computer systems made partial copies of records across systems because all business was being conducted locally and computer-to-computer communications were not reliable.<\/p>\n\n\n\n<p><strong>A combination of the <em>identifier<\/em> and <em>location<\/em> can be used to uniquely identify a specific parcel, preserving the historical accuracy of information and streamlining information sharing across industries.<\/strong> The technical term for this is a <em>compound key<\/em>, a well-known and widely implemented approach to similar situations.  <\/p>\n\n\n\n<p>Parcel identifiers can be called by different names depending on the area of the country being searched.  Most of the US record keeping is conducted at the county level, but I will cover that topic a little later in this article.  The identifier name is part of the professional vocabulary of the area and reflects historical record-keeping practices.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>APN<\/strong> &#8211; Assessor Parcel Number<\/li>\n\n\n\n<li><strong>AIN<\/strong> &#8211; Assessor Identification Number<\/li>\n\n\n\n<li><strong>ASMT<\/strong> &#8211; Assessment<\/li>\n\n\n\n<li><strong>Fee <\/strong>&#8211; Fee Number<\/li>\n\n\n\n<li><strong>PAN<\/strong> &#8211; Property Account Number<\/li>\n\n\n\n<li><strong>PID<\/strong> &#8211; Parcel Identifier<\/li>\n\n\n\n<li><strong>PIN<\/strong> &#8211; Property Identification Number<\/li>\n\n\n\n<li><strong>SBL<\/strong> &#8211; Section-Block-Lot Number<\/li>\n\n\n\n<li><strong>Sidwell<\/strong> &#8211; Sidwell Number<\/li>\n\n\n\n<li><strong>TAN<\/strong> &#8211; Tax Account Number<\/li>\n<\/ul>\n\n\n\n<p>The format of these identifiers varies as presented in the following table.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"594\" src=\"https:\/\/lesswing.com\/wp-content\/uploads\/2024\/03\/parcel-identifier-study-march-2024.png\" alt=\"\" class=\"wp-image-1134\" style=\"width:439px;height:auto\" srcset=\"https:\/\/lesswing.com\/wp-content\/uploads\/2024\/03\/parcel-identifier-study-march-2024.png 300w, https:\/\/lesswing.com\/wp-content\/uploads\/2024\/03\/parcel-identifier-study-march-2024-152x300.png 152w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/figure>\n\n\n\n<p>The spaces, dashes and periods are important to preserve. Trying to decipher the identifier can be a daunting task given there are over 3,000 counties in the US. <strong>The <em>identifier<\/em> should be handled as a single (and opaque) string in software<\/strong>.  If you simply remove punctuation, it is difficult to discriminate between 0011-01 and 001-101<strong>.<\/strong><\/p>\n\n\n\n<p>Identifiers are typically issued at the county level.  Some cities (or towns) manage their parcels separately which can result in the same <em>identifier<\/em> being used for different properties located in the same county.  The <a href=\"https:\/\/www2.census.gov\/geo\/docs\/reference\/codes2020\/national_cousub2020.txt\" data-type=\"link\" data-id=\"https:\/\/www2.census.gov\/geo\/docs\/reference\/codes2020\/national_cousub2020.txt\">US Census Bureau<\/a> breaks down counties into legal geographies called <a href=\"https:\/\/www2.census.gov\/geo\/pdfs\/reference\/GARM\/Ch8GARM.pdf\" data-type=\"link\" data-id=\"https:\/\/www2.census.gov\/geo\/pdfs\/reference\/GARM\/Ch8GARM.pdf\"><em>County Subdivisions<\/em> <\/a>(or <em>sub-counties<\/em>) which are <a href=\"https:\/\/www.census.gov\/library\/reference\/code-lists\/ansi.html#cousub\" data-type=\"link\" data-id=\"https:\/\/www.census.gov\/library\/reference\/code-lists\/ansi.html#cousub\">townships and cities<\/a>.  Here is an example of Census Bureau County Subdivision information for an address taken from the <a href=\"https:\/\/geocoding.geo.census.gov\/geocoder\/geographies\/onelineaddress?form\" data-type=\"link\" data-id=\"https:\/\/geocoding.geo.census.gov\/geocoder\/geographies\/onelineaddress?form\">census geocoder<\/a> :<\/p>\n\n\n\n<p><strong>Address:<\/strong> XXX Adele Lane in Bronxville, NY 10708<\/p>\n\n\n\n<figure class=\"wp-block-image size-full is-resized is-style-default\"><img loading=\"lazy\" decoding=\"async\" width=\"420\" height=\"492\" src=\"https:\/\/lesswing.com\/wp-content\/uploads\/2024\/03\/Subcounty-Lookuo.png\" alt=\"\" class=\"wp-image-1135\" style=\"width:210px;height:auto\" srcset=\"https:\/\/lesswing.com\/wp-content\/uploads\/2024\/03\/Subcounty-Lookuo.png 420w, https:\/\/lesswing.com\/wp-content\/uploads\/2024\/03\/Subcounty-Lookuo-256x300.png 256w\" sizes=\"auto, (max-width: 420px) 100vw, 420px\" \/><\/figure>\n\n\n\n<p>The following information is taken from the search results:<\/p>\n\n\n\n<p><strong>State<\/strong>: 36 (New York)<br><strong>County:<\/strong> 119 (Westchester)<br><strong>Sub-county<\/strong> (COUSUB): 84000 (Yonkers)<br><strong>GEOID:<\/strong> 3611984000<\/p>\n\n\n\n<p>Although the address is in Bronxville, the <em>Sub-county<\/em> is Yonkers, not Westchester.  The <em>State<\/em> and <em>County<\/em> numbers are called <a href=\"https:\/\/transition.fcc.gov\/oet\/info\/maps\/census\/fips\/fips.txt\" data-type=\"link\" data-id=\"https:\/\/transition.fcc.gov\/oet\/info\/maps\/census\/fips\/fips.txt\">FIPS codes<\/a> used by many government data sources. The <em>GEOID<\/em> is a combination of <em>State<\/em>, <em>County<\/em> and <em>Sub-county<\/em> identifiers. Using a <em>GEOID<\/em> location with the <em>identifier<\/em> guarantees that it will be unique.  It does not mean that the local government issued the <em>identifier<\/em>, but it does guarantee that the <em>GEOID\/ide<\/em>ntifier pair is unique.<\/p>\n\n\n\n<p>Jargon is important to any conversation, so I will define some terms now for clarity.  A good term for <em>GEOID<\/em> is <em>Subcountry<\/em> (not to be confused with &#8220;Sub-county&#8221;) because many other countries (including Canada) maintain location identifiers similar to <em>GEOID<\/em>.  In Germany and other countries in Europe, the <a href=\"https:\/\/en.wikipedia.org\/wiki\/NUTS_statistical_regions_of_Germany\">NUTS-3<\/a> number would be the GEOID equivalent. There are many identifiers in computer systems so we will call ours<em> Parcel<\/em>. <strong>The combination of <em>Subcountry<\/em> and <em>Parcel<\/em> is unique across the US and adding an <a href=\"https:\/\/www.iso.org\/iso-3166-country-codes.html\" data-type=\"link\" data-id=\"https:\/\/www.iso.org\/iso-3166-country-codes.html\">ISO 3166<\/a> country code creates an international identification system<\/strong>.<\/p>\n\n\n\n<p><strong>Country<\/strong>: US &#8211; International Standard<br><strong>Subcountry<\/strong>: 3611984000 &#8211; Legal geography within a country<br><strong>Parcel<\/strong>: &#8220;5-5248-603-0&#8221; &#8211; An identifier used within a legal geography<\/p>\n\n\n\n<p><strong>Unique Identifier<\/strong> &#8211; &#8220;US&#8221; + &#8220;3611984000&#8221; + &#8220;5-5248-603-0&#8221;<\/p>\n\n\n\n<p>Here is another example that demonstrates the approach in use with a more complex <em>Parcel<\/em> in Pennsylvania:<\/p>\n\n\n\n<p><strong>Unique Identifier<\/strong> &#8211; &#8220;US&#8221; + &#8220;4204949548&#8221; + &#8220;14 032 051.0 229.00a&#8221;<\/p>\n\n\n\n<p>If you wanted to pull the key apart and use pieces of the <em>compound key<\/em> (&#8220;only show me addresses in Canada&#8221;), it should be created with a separator.  Common separators are periods, commas and dashes.  Unfortunately, the <em>Parcel<\/em> can contain these characters foiling the scheme.   We can either a) store and pass multiple fields or b) consider using a single field <a href=\"https:\/\/auth0.com\/blog\/url-uri-urn-differences\/\" data-type=\"link\" data-id=\"https:\/\/auth0.com\/blog\/url-uri-urn-differences\/\">URN<\/a> as documented in <a href=\"https:\/\/datatracker.ietf.org\/doc\/html\/rfc2141\" data-type=\"link\" data-id=\"https:\/\/datatracker.ietf.org\/doc\/html\/rfc2141\">IETF RFC 2841<\/a>.  The Universal Property Identifier workgroup of <a href=\"https:\/\/www.reso.org\/upi-workgroup\/\" data-type=\"link\" data-id=\"https:\/\/www.reso.org\/upi-workgroup\/\">RESO<\/a> is working on these issues to make cross-system referencing easier. <\/p>\n\n\n\n<p><strong>Mapping a <em>compound key<\/em> to an address allows consumers to drive the process with familiar addresses and the systems behind the experience to communicate efficiently.<\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Consumers refer to properties using an address but when buying and selling, what changes hands is called a parcel. Counties record parcel transfers to protect owners&#8217; real property rights. Parcels pre-date the postal system. Record keeping is performed at the parcel level because it is possible to sell real estate that does not have a [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":1131,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[31,36,56,67],"tags":[26,42],"class_list":["post-1132","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-consumer","category-legacy-integration","category-standards","category-synchronization","tag-consumer","tag-integration"],"_links":{"self":[{"href":"https:\/\/lesswing.com\/index.php\/wp-json\/wp\/v2\/posts\/1132","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lesswing.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lesswing.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lesswing.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/lesswing.com\/index.php\/wp-json\/wp\/v2\/comments?post=1132"}],"version-history":[{"count":81,"href":"https:\/\/lesswing.com\/index.php\/wp-json\/wp\/v2\/posts\/1132\/revisions"}],"predecessor-version":[{"id":1217,"href":"https:\/\/lesswing.com\/index.php\/wp-json\/wp\/v2\/posts\/1132\/revisions\/1217"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/lesswing.com\/index.php\/wp-json\/wp\/v2\/media\/1131"}],"wp:attachment":[{"href":"https:\/\/lesswing.com\/index.php\/wp-json\/wp\/v2\/media?parent=1132"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lesswing.com\/index.php\/wp-json\/wp\/v2\/categories?post=1132"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lesswing.com\/index.php\/wp-json\/wp\/v2\/tags?post=1132"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}