Blog · September 30, 2026
What a Surveyor Cap Number Means
A survey cap is the plastic or metal head on a rod or pipe, stamped with the surveyor’s name or license number. The number identifies who set that mark. It does not by itself prove the rod is your property corner.
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What is stamped on the cap
Many states require a surveyor who sets a monument to identify it. The cap may carry a personal name, a company name, a license number, or all three. On the plat, the legend may say iron rod with cap stamped RLS 1234, or a similar phrase using that state’s credential abbreviation. Copy the stamp as written. The number lets a later surveyor look up who set the mark and find that surveyor’s plat or corner record. It is an identification, not a deed. A cap from a firm you do not recognize can still be the monument called for on the subdivision plat.
Plastic cap, aluminum cap, and no cap
Plastic caps are common on rebar. Aluminum or brass caps are common on pipes and on section-corner monuments. Older irons may have no cap at all. Absence of a cap does not erase a monument the record calls for as a plain pipe or a stone. Presence of a cap does not upgrade a rod that the plat never mentioned. Match the object the plat describes. If the plat says a 5/8-inch rod with a yellow cap, a bare half-inch rod a few feet away is a different object until a surveyor decides otherwise. Several capped rods in one hole are a separate problem, often called a pin cushion, and the stamps help sort who set which one.
What the number does not authorize
The license number does not give you permission to pull the cap, and it does not make a consumer GPS reading match the corner. Platbookmapper does not display caps or license numbers. It links to the county GIS map, which is an assessment picture, not a monument inventory. To tie a cap number to a recorded survey, you use the plat, the corner record, or the record of survey that cites that number. If the cap is the only mark you have found and no plat mentions it, write down the stamp and the general location and ask a surveyor. Do not move a fence to an unidentified cap.
What to do next
- Read the legend for the cap stamp the plat expects.
- Copy the number or name exactly, including letters.
- Match material and size, not just the fact that a cap is present.
- Leave the cap in place. Identification is done by reading it, not by removing it.
The mix-up to avoid
Assuming any capped rod with a number on it is the lot corner. Caps mark who set the rod. Only the plat, the deed, and a surveyor’s recovery say whether that rod is the corner.
Questions people ask
Can I look up the license number and call that surveyor?
Often yes, through the state licensing board’s public roster, which will tell you whether the number was issued. The roster is not a survey of your lot. The surveyor who set the cap may be retired, and the plat that shows the cap is still the document to read.
What if the cap is broken off?
Note that the head is gone and describe the rod that remains. A broken cap does not automatically void the monument. It does make identification harder, which is a reason to have a surveyor compare it with the record instead of guessing.
Find the county map
Search the county on the Platbookmapper home page. The directory links to the official parcel viewer. It does not draw the lots, and the line on the screen is an assessment map, not a survey.
Not a survey. County GIS and tax parcel maps are assessment and planning layers. They are not a substitute for a recorded plat, deed, or licensed survey.