Can any one help to clarify my question?

Hi.

BillingCurrency should always be populated for both exisiting users and anonymous. The Code listet below is from the CartHelper implementation. This code sample is from 7.5, but I do not think this implementation has changed appart from Market. The market feature was included in R3 (API) and fully functional from 7.5.

  public Cart GetCart(string name, Guid customerId, MarketId marketId)
        {
            Cart cart = Cart.LoadCartsByCustomerAndName(customerId, name).SingleOrDefault<Cart>((Cart c) => c.MarketId == marketId) ?? this.CreateCart(name, customerId, marketId);
            return cart;
        }

  private Cart CreateCart(string name, Guid customerId, MarketId marketId)
        {
            if (string.IsNullOrEmpty(name))
            {
                throw new ArgumentException("Name parameter can't be null or empty", "name");
            }
            if (customerId == Guid.Empty)
            {
                throw new ArgumentException("CustomerId parameter can't be null or empty", "customerId");
            }
            Cart currencyCode = (Cart)OrderContext.Current.ShoppingCartClassInfo.CreateInstance();
            currencyCode.Name = name;
            currencyCode.BillingCurrency = CommonSettingsManager.GetDefaultCurrency().CurrencyCode;
            currencyCode.CustomerId = customerId;
            currencyCode.MarketId = marketId;
            return currencyCode;
        }

Mediachase.Commerce.Shared.CurrencyFormatter.FormatCurrency(YourPrice, DefaultCart.BillingCurrency)

DefaultCart is Mediachase.Commerce.Orders.Cart

/K