public class TrimModelBinder : IModelBinder
 {
 public object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
 {
 var valueResult = bindingContext.ValueProvider.GetValue(bindingContext.ModelName);
 string attemptedValue = valueResult?.AttemptedValue;

 return string.IsNullOrWhiteSpace(attemptedValue) ? attemptedValue : attemptedValue.Trim();
 }
 }

protected void Application_Start()
 {
 //System.Web.Mvc.ModelBinders.Binders.DefaultBinder = new ModelBinders.TrimModelBinder();
 System.Web.Mvc.ModelBinders.Binders.Add(typeof(string), new ModelBinders.TrimModelBinder());
 AreaRegistration.RegisterAllAreas();
 FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
 RouteConfig.RegisterRoutes(RouteTable.Routes);
 BundleConfig.RegisterBundles(BundleTable.Bundles);
 }

public class TrimModelBinder : ComplexTypeModelBinder
 {
 public TrimModelBinder(IDictionary propertyBinders) : base(propertyBinders) { }
 
 protected override void SetProperty(ModelBindingContext bindingContext, string modelName, ModelMetadata propertyMetadata, ModelBindingResult result)
 {
 var value = result.Model as string;
 
 result= string.IsNullOrWhiteSpace(value) ? result : ModelBindingResult.Success(value.Trim());
 
 base.SetProperty(bindingContext, modelName, propertyMetadata, result);
 }
 }

public class TrimModelBinderProvider : IModelBinderProvider
 {
 public IModelBinder GetBinder(ModelBinderProviderContext context)
 {
 if (context.Metadata.IsComplexType && !context.Metadata.IsCollectionType)
 {
 var propertyBinders = new Dictionary();
 for (int i = 0; i < context.Metadata.Properties.Count; i++)
 {
 var property = context.Metadata.Properties[i];
 propertyBinders.Add(property, context.CreateBinder(property));
 }
 return new TrimModelBinder(propertyBinders);
 }
 return null;
 }
 }

services.AddMvc().AddMvcOptions(s =>
 {
 s.ModelBinderProviders[s.ModelBinderProviders.TakeWhile(p => !(p is ComplexTypeModelBinderProvider)).Count()] = new TrimModelBinderProvider();
 });