The SQL Server database is a relational database management system used all over the world. And just because SQL is used so much doesn’t mean it’s immune to errors. A common error when logging into the SQL server is error 18456 and this is the error message that is displayed on the screen –
Login failed for user. The user is not associated with a trusted SQL Server connection.
When users try to connect to the SQL Server through the login authentication system, rather than granting access to the user, the server generates error 18456. Sometimes the error also says that it is status 1, which is almost the same as the main error, because all other variations of error 18456 are converted to status 1 error for security reasons.
As you can see, Microsoft is not so helpful when it comes to providing details about error messages.
Reasons behind SQL Server error 18456
Verification issue: Logging in from the new system for the first time may also be the cause of this error. The good part is – it’s nothing important. The error is caused because the server is set to Windows authentication mode. Change the mode and try to log in again. The error must be corrected
Wrong credentials: This is probably the most common reason for error 18456 and yet we want to focus on the smallest details. Check if your login details are correct. When logging in for the first time, make sure you have received the correct login details from the administrator.
User ID disabled: If the user ID has not been able to access the SQL server, this error will be generated. Again, if you are trying to log in for the first time, we recommend that you contact the administrator to ensure that your user ID has been accessed.
Different states of the error: As we said, there are different states of the error and once you know what the different states mean, it is easier to solve the problem:
If the error status is 2 or 5, it means that the user ID is invalid and you should check that.
Error status 6 means that the user is trying to use a Windows login name for SQL authentication that the server cannot understand.
An error status of 7 means the login is disabled or the password does not match
Error status 8 means that a password does not match
Error status 9 implies an invalid password
Error status 11 and 12 means that the credentials are correct, but there is a server access error.
Error status 13 means that the SQL server has been interrupted
Error status 18 means that the password has expired and needs to be changed
If the error status is anything other than this, it’s probably an internal error and you should contact your administrator before doing anything.
Final words: SQL Server 18456 error is a login error that can be easily resolved by a few troubleshooting steps. Usually the problems can be solved immediately. Make sure to always check your references before doing anything else.