An air carrier descended to FL240, the controller advised that FL250 was issued.

Attributes
ACN	316270
Time
Date	199509
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : wal
State Reference	FO
Altitude	msl bound lower : 24000 msl bound upper : 25000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : egpx
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	descent other
Route In Use	enroute : atlantic enroute : on vectors enroute other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time total : 17000
ASRS Report	316270
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	altitude deviation : overshoot altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation Operational Deviation

Narrative:

My flight was cleared to descend to FL240. Reaching FL240 scottish control advised that the clearance was to FL250. Flight was then cleared to maintain FL240.

Original NASA ASRS Text

Title: AN ACR DSNDED TO FL240, THE CTLR ADVISED THAT FL250 WAS ISSUED.

Narrative: MY FLT WAS CLRED TO DSND TO FL240. REACHING FL240 SCOTTISH CTL ADVISED THAT THE CLRNC WAS TO FL250. FLT WAS THEN CLRED TO MAINTAIN FL240.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.