How to verify address by Microsoft Bing map geo service?

Add  GeocodeService webserivice into your project
http://dev.virtualearth.net/webservices/v1/geocodeservice/geocodeservice.svc?wsdl

        private bool GeocodeAddress(string address)

        {

            GeoLocation results = null ;

            string key = "Bing map key";

            GeocodeRequest geocodeRequest = new GeocodeRequest();

            // Set the credentials using a valid Bing Maps key

            geocodeRequest.Credentials = new Credentials();

            geocodeRequest.Credentials.ApplicationId = key;

            // Set the full address query

            geocodeRequest.Query = address;

            // Set the options to only return high confidence results 

            ConfidenceFilter[] filters = new ConfidenceFilter[1];

            filters[0] = new ConfidenceFilter();

            filters[0].MinimumConfidence = Confidence.High;

            // Add the filters to the options

            GeocodeOptions geocodeOptions = new GeocodeOptions();

            geocodeOptions.Filters = filters;

            geocodeRequest.Options = geocodeOptions;

            // Make the geocode request

            Registration.GeocodeService.GeocodeService geocodeService = new  GeocodeService.GeocodeService();

            GeocodeResponse geocodeResponse = geocodeService.Geocode(geocodeRequest);

            if (geocodeResponse.Results.Length > 0)

            {

                Return true;

            }

            Return false;

        }

Reference:

http://msdn.microsoft.com/en-us/library/dd221354.aspx