Connecting to Oracle Pluggable database using service name I installed Oracle 12c on windows using all the defaults but choosing to use a pluggable database and to install the sample data. The container database and SID name is ORCL and the pluggable database is PDBORCL.

I noticed that using SQL Developer I can connect to the pluggable database by using its name as the service name. Also I can connect to the container database using its name either as SID or service name. 

Looking at my tnsnames.ora I found that only ORCL is mentioned as a service name. Does oracle register pluggable databases as service names automatically or there is a configuration file that I am missing?
It registers them automatically. 

Very easy to test...

Listener status shows no PDB:

$ lsnrctl status

LSNRCTL for Linux: Version 12.1.0.1.0 - Production on 13-MAR-2015 09:41:15

Copyright (c) 1991, 2013, Oracle.  All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=localhost.localdomain)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version                   TNSLSNR for Linux: Version 12.1.0.2.0 - Production
Start Date                04-MAR-2015 15:03:10
Uptime                    8 days 18 hr. 38 min. 6 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Listener Parameter File   /u01/app/oracle/product/12.1.0.2/network/admin/listener.ora
Listener Log File         /u01/app/oracle/diag/tnslsnr/localhost/listener/alert/log.xml
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=localhost.localdomain)(PORT=1521)))
Services Summary...
Service "CDB1" has 1 instance(s).
  Instance "CDB1", status READY, has 1 handler(s) for this service...
Service "CDB1XDB" has 1 instance(s).
  Instance "CDB1", status READY, has 1 handler(s) for this service...
Service "UPGR" has 1 instance(s).
  Instance "UPGR", status READY, has 1 handler(s) for this service...
Service "UPGRXDB" has 1 instance(s).
  Instance "UPGR", status READY, has 1 handler(s) for this service...
The command completed successfully
[CDB1] oracle@localhost:/u01/app/oracle/product/11.2.0
$ echo $ORACLE_SID
CDB1
[CDB1] oracle@localhost:/u01/app/oracle/product/11.2.0


Create a new PDB:

$ sqlplus / as sysdba

SQL*Plus: Release 12.1.0.1.0 Production on Fri Mar 13 09:41:27 2015

Copyright (c) 1982, 2013, Oracle.  All rights reserved.


Connected to:
Oracle Database 12c Enterprise Edition Release 12.1.0.1.0 - 64bit Production
With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options

create pluggable database pdb_phil
admin user phil identified by phil
  3  file_name_convert = ('/pdbseed/', '/pdb_phil/');

Pluggable database created.

SQL&gt; col name for a20
SQL&gt; col open_mode for a10
SQL&gt; select con_id, dbid, name, open_mode from v$pdbs;

    CON_ID       DBID NAME                 OPEN_MODE
---------- ---------- -------------------- ----------
         2 4096360259 PDB$SEED             READ ONLY
         3 3580684491 PDB_PHIL             MOUNTED

SQL&gt; quit


It is now registered with the listener:

$ lsnrctl status

LSNRCTL for Linux: Version 12.1.0.1.0 - Production on 13-MAR-2015 09:44:06

Copyright (c) 1991, 2013, Oracle.  All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=localhost.localdomain)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version                   TNSLSNR for Linux: Version 12.1.0.2.0 - Production
Start Date                04-MAR-2015 15:03:10
Uptime                    8 days 18 hr. 40 min. 57 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Listener Parameter File   /u01/app/oracle/product/12.1.0.2/network/admin/listener.ora
Listener Log File         /u01/app/oracle/diag/tnslsnr/localhost/listener/alert/log.xml
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=localhost.localdomain)(PORT=1521)))
Services Summary...
Service "CDB1" has 1 instance(s).
  Instance "CDB1", status READY, has 1 handler(s) for this service...
Service "CDB1XDB" has 1 instance(s).
  Instance "CDB1", status READY, has 1 handler(s) for this service...
Service "UPGR" has 1 instance(s).
  Instance "UPGR", status READY, has 1 handler(s) for this service...
Service "UPGRXDB" has 1 instance(s).
  Instance "UPGR", status READY, has 1 handler(s) for this service...
Service "pdb_phil" has 1 instance(s).
  Instance "CDB1", status READY, has 1 handler(s) for this service...
The command completed successfully
[CDB1] oracle@localhost:/u01/app/oracle/product/11.2.0
$