Misunderstanding clearance, flight crew climbed to FL220 instead of FL200.

Attributes
ACN	348100
Time
Date	199609
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : ind
State Reference	IN
Altitude	msl bound lower : 20000 msl bound upper : 22000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zid
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 210 flight time total : 20000 flight time type : 8000
ASRS Report	348100
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	altitude deviation : overshoot non adherence : clearance non adherence : far
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

ATC gave us FL220 I confirmed by reading back FL220, my first officer confirmed by saying FL220. After reaching FL220 ATC asked us our altitude. We answered level FL220. His response was you were cleared to FL200. I asked if he wanted us to descend to FL200 he said no, remain level at FL220.

Original NASA ASRS Text

Title: MISUNDERSTANDING CLRNC, FLC CLBED TO FL220 INSTEAD OF FL200.

Narrative: ATC GAVE US FL220 I CONFIRMED BY READING BACK FL220, MY FO CONFIRMED BY SAYING FL220. AFTER REACHING FL220 ATC ASKED US OUR ALT. WE ANSWERED LEVEL FL220. HIS RESPONSE WAS YOU WERE CLRED TO FL200. I ASKED IF HE WANTED US TO DSND TO FL200 HE SAID NO, REMAIN LEVEL AT FL220.

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.