Sullivan County Property Tax Appeal — Deadline and How to File
The deadline
Filing deadline
September 1
per the Sullivan County Board of Assessment Appeals' Appeal Rules, checked 2026-09-11 — source
Who hears it, and where it goes
Your appeal is decided by the Sullivan County Board of Assessment Appeals.
Where to file
Sullivan County Assessment OfficeP.O. Box 157
Laporte, PA 18626
The form: Assessment Appeal form.
Filed by mail or in person at the Sullivan County Courthouse, Monday to Friday, 8:30 AM to 4:00 PM.
An appeal received after the deadline is rejected, even if it was mailed earlier.
per the Sullivan County Assessment Office's Appeal Rules, checked 2026-09-11 — source
Nearby counties
- Bradford County — Bradford County Board of Assessment and Revision of Taxes
- Wyoming County — Wyoming County Board of Assessment Appeals
- Lycoming County — Lycoming County Board of Assessment Appeals
- Luzerne County — Luzerne County Board of Tax Assessment Appeals
- Montour County — Montour County Board of Assessment Appeals
- Northumberland County — Northumberland County Board of Assessment Revision
More: the county index and the Pennsylvania guide.
What your assessed value means here
Pennsylvania — assessed at a base-year value; the STEB Common Level Ratio for your county is about 40.49% of current market. Confirm the ratio on your notice (53 Pa.C.S. §8854).
Sullivan County's common level ratio is drawn from the 2025 CLR (2024 sales data; effective 7/1/2026–6/30/2027) table — the same figure the app uses to compare your assessment to current market value.
Can the board raise your assessment?
Yes. The Sullivan County Board of Assessment Appeals can raise your assessment on your own appeal, not only lower it. That is the risk you take by filing, and it is why the case has to be worth making before you file it.
What a board actually weighs
The Sullivan County Board of Assessment Appeals decides what your property was worth on the valuation date, so recent comparable sales carry the case, not the size of the bill. The Pennsylvania guide covers the evidence.
Common questions
- When is the deadline to appeal my property assessment in Sullivan County?
- The deadline is September 1 — per the Sullivan County Board of Assessment Appeals' Appeal Rules, checked 2026-09-11.
- Who decides my appeal in Sullivan County?
- The Sullivan County Board of Assessment Appeals.
- Where do I send my appeal in Sullivan County?
- To the Sullivan County Assessment Office, P.O. Box 157, Laporte, PA 18626 — per the Sullivan County Assessment Office's Appeal Rules, checked 2026-09-11. The form is the Assessment Appeal form.
Sources
Property tax rules and deadlines vary by jurisdiction and can change — verify with your county before relying on this.
PROppeal is coming soon for Sullivan County
When it launches, PROppeal will check your case against real, recent comparable sales and give you an honest verdict — then build the board-ready letter to file — $29.99, no percentage of your savings.
Want a heads-up when it’s live? Email [email protected].