The Horry County Assessor's Office appraises and lists all real property for taxation and maintains ownership information. It reviews legal residence (or primary residence) applications, agriculture assessments, and many other ownership functions.


The Horry County Assessor’s Office announces the official move from TMS to PIN’s. (TMS refers to Tax Map Submap numbers for parcels and PIN refers to Parcel Identification Number.) The Assessor’s office is deploying new appraisal software to enable staff to effectively manage mass property appraisals. As a part of this project, a conversion from the TMS numbering system to the GIS based PIN numbering system takes effect.


Rapid development in recent years has required the change to a new system. The TMS system was based on a Map, submap, block, parcel numbering scheme. Two problems were arising due to the growth: 1) Submap (2 digits) was limited to 99 submaps per map. 2) Parcel numbers (3 digits) were limited to 999 per block. Essentially, the potential existed in highly developed areas of the county to eventually run out of parcel numbers. This also was being complicated by the need in new database systems to retire parent parcels to insure a consistent history trail. GIS technology has also changed the manner in which parcel numbering schemes are developed. GIS enables the auto generation of parcel numbers based on location and Grid based standards. Land development and technology advancements impact the need for change.

How it Works

In the past TMS numbers were generated manually. As development occurred new submap areas were created, new block lines drawn in. Both of these were random and based on the density of development.

Grid based parcel numbers are assigned based on location within the master grid and the location of submaps and blocks is standard from one map to the next. (See the example above.) The Grid above is repeated consistently over the county. The Red square represents the Map number and corresponds to the first 3 digits of the PIN. The Blue lines represent the submap area. Each Map contains 16 submaps and and corresponds to the next 2 digits in the PIN. The Green lines represent the blocks. Each submap contains 4 blocks and corresponds to the next 2 digits in the PIN. The Black lines represent the parcel and corresponds to the last 4 digits in the PIN. This substantially increases the potential to 9999 parcels per block, previously limited to 999 per block. Additionally, by looking at the PIN it becomes evident as to the general location of a parcel in the overall map scheme consistently anywhere in the County.

During the transition period all parcels will be issued both a TMS number (10 digits) and a PIN (11 digits). Citizens will begin seeing both numbers associated with parcel information including tax bills. TMS numbers will be retained for reference purposes, eventually all new parcels will be issued PIN’s only and no TMS numbers.

TMS to PIN Conversion Tool

EFFECTIVE January 1, 2014: TMS numbers will no longer be issued on new parcels, only PINs.

Horry County TMS to PIN

Grid Legend

Red Map (3 Digits)
Blue Submap (2 Digits)
Green Block (2 Digits)
Black Parcel Lines (4 Digits)
PIN = xxx-xx-xx-xxxx
PIN = Map-Submap-Block-Parcel