Google Product Forums

Re: the Maximum number of possible values in each defined custom value...

Eduardo Cereto Mar 26, 2012 2:41 PM
Posted in group: Google Analytics
If you're talking about values for a single custom Variable there are no limits except the default table limits for GA.

Any table in GA is limited to 50k values.

Please also take note that sending usernames or any other PII (Personally identifiable information) to gA is forbidden per the ToS.

More info regardin table limits;