Identify Orphan Users on an instance

Many a time when we move our database to new instance, rebuilding server or setting up a backup we need to synchronize user logins with the server

We can use below script to find out the Orphan Users on the Server

IF EXISTS (SELECT * FROM sysobjects WHERE id = OBJECT_ID(N'[dbo].[usp_ShowOrphanUsers]') AND OBJECTPROPERTY(id, N'IsProcedure') = 1)
DROP PROCEDURE [dbo].[usp_ShowOrphanUsers]
GO

CREATE PROC dbo.usp_ShowOrphanUsers
AS
BEGIN
CREATE TABLE #Results
([Database Name] sysname ,
[Orphaned User] sysname ,
[Type User] sysname )

SET NOCOUNT ON

DECLARE @DBName sysname, @Qry NVARCHAR(4000)

SET @Qry = ''
SET @DBName = ''

WHILE @DBName IS NOT NULL
BEGIN
SET @DBName =
(
SELECT MIN(name)
FROM master..sysdatabases
WHERE name NOT IN
('master', 'model', 'tempdb', 'msdb', 'distribution', 'pubs', 'northwind', 'dba_database')
AND DATABASEPROPERTY(name, 'IsOffline') = 0
AND DATABASEPROPERTY(name, 'IsSuspect') = 0
AND name > @DBName
)

IF @DBName IS NULL BREAK

SET @Qry = ' SELECT ''' + @DBName + ''' AS [Database Name],
CAST(name AS sysname) COLLATE Latin1_General_CI_AS AS [Orphaned User],
[Type User] =
CASE isntuser
WHEN ''0'' THEN ''SQL User''
WHEN ''1'' THEN ''NT User''
ELSE ''Not Available''
END
FROM ' + QUOTENAME(@DBName) + '..sysusers su
WHERE su.islogin = 1
AND su.name NOT IN (''INFORMATION_SCHEMA'', ''sys'', ''guest'', ''dbo'', ''system_function_schema'')
AND NOT EXISTS (SELECT 1 FROM master..syslogins sl WHERE su.sid = sl.sid)'
INSERT INTO #Results
EXEC master..sp_executesql @Qry
END
SELECT *
FROM #Results
ORDER BY [Database Name], [Orphaned User]
IF @@ROWCOUNT = 0
PRINT 'No orphaned users exist in this server.'
END
GO

--Execute the proc
EXEC [dbo].[usp_ShowOrphanUsers]

"This script is taken from SQL Server Central"