Termite vs WDO vs WDI vs Clearance Letter — What's the Difference?

The same inspection goes by several names. Here's what each means and which one your lender needs.

✓ Reviewed June 23, 2026 · sources: NPMA, VA, CA Structural Pest Control Board

In short: WDO ⊇ WDI ⊇ "termite inspection". A clearance letter is the result, not the inspection — and the lender's document is usually Form NPMA-33.

The terms compared

Wood-destroying inspection terminology — US, 2026
Term	Scope	Where used
WDO inspection	Broadest — termites + carpenter ants/bees + wood-boring beetles + wood-decay fungi	Florida, California
WDI inspection	Wood-destroying insects (no fungi in some states)	Texas, VA program
Termite inspection	Narrowest — termites only	Colloquial everywhere
Clearance letter	Document of result after treatment (not an inspection)	Nationwide; CA = clear Section 1
NPMA-33	The standard report form lenders accept	VA, most mortgages

So when a lender, agent or contract says "termite letter," "WDO," "WDI," or "termite clearance," they're almost always pointing at the same thing: a professional wood-destroying inspection documented on Form NPMA-33 (from the National Pest Management Association), plus a clearance if treatment was needed. For VA loans the WDI report is the standard.

California: Section 1 vs Section 2

California WDO reports split findings into sections. Section 1 = active infestation or existing damage (live termites, fungus, dryrot) — usually must be corrected to get a Section 1 clearance before a lender funds. Section 2 = conditions likely to lead to infestation (e.g., wood-to-soil contact, leaks) — disclosed but not required to be fixed to close. The state body overseeing this is the California Structural Pest Control Board.

Practical takeaway: don't get hung up on the label. Ask your lender which form they need (almost always NPMA-33), use an inspector licensed for it in your state, and budget for a possible clearance if anything active turns up.

Key terms

WDO: Wood-destroying organism — termites, other insects, and wood-decay fungi.
WDI: Wood-destroying insect — insects only; the VA/Texas term.
NPMA-33: The standard national inspection report form lenders accept.
Clearance letter: Post-treatment proof of no active infestation (CA: clear Section 1).

Common questions

Is a WDO inspection the same as a termite inspection?

Not exactly. A WDO (wood-destroying organism) inspection is broader — it covers termites plus other wood-destroying insects and wood-decay fungi. A plain termite inspection looks only for termites. Lenders generally want a WDO or WDI inspection, documented on Form NPMA-33, not just a termite-only check.

What is the difference between WDO and WDI?

WDI (wood-destroying insect) covers insects only and is the term used in Texas and the VA program; WDO (wood-destroying organism) also includes wood-decay fungi and is the common term in Florida and California. Both are typically reported on Form NPMA-33.

Is a clearance letter the same as the inspection?

No. The inspection produces a report; the clearance letter is the document issued after any required treatment confirming the property is free of active infestation in the cited areas. In California this is a clear Section 1 report.

What are California Section 1 and Section 2?

On a California WDO report, Section 1 lists active infestation or existing damage (live termites, fungus, dryrot) that usually must be corrected to get a clearance before a lender funds. Section 2 lists conditions likely to lead to infestation (like wood-to-soil contact); it is disclosed but not required to be fixed to close.

Sources

Form NPMA-33 & inspection standards — National Pest Management Association, accessed Jun 2026
VA WDI requirement — benefits.va.gov (Circular 26-22-11), accessed Jun 2026
California Section 1/2 & licensing — California Structural Pest Control Board, accessed Jun 2026