changed the address data used to pull sales tax for premium subscriptions (#1109)

* changed the address data used to pull sales tax for premium subscriptions

* nulled checked for extra safety

* fixes null check

src/Core/Services/Implementations/StripePaymentService.cs

@@ -444,20 +444,24 @@ namespace Bit.Core.Services
                 Quantity = 1,
             });
 
-            var taxRates = await _taxRateRepository.GetByLocationAsync(
-                new Bit.Core.Models.Table.TaxRate()
+            if (!string.IsNullOrWhiteSpace(taxInfo?.BillingAddressCountry) 
+                    && !string.IsNullOrWhiteSpace(taxInfo?.BillingAddressPostalCode)) 
+            {
+                var taxRates = await _taxRateRepository.GetByLocationAsync(
+                    new Bit.Core.Models.Table.TaxRate()
+                    {
+                        Country = taxInfo.BillingAddressCountry,
+                        PostalCode = taxInfo.BillingAddressPostalCode
+                    }
+                );
+                var taxRate = taxRates.FirstOrDefault();
+                if (taxRate != null)
                 {
-                    Country = customer.Address.Country,
-                    PostalCode = customer.Address.PostalCode
+                    subCreateOptions.DefaultTaxRates = new List<string>(1) 
+                    { 
+                        taxRate.Id 
+                    };
                 }
-            );
-            var taxRate = taxRates.FirstOrDefault();
-            if (taxRate != null)
-            {
-                subCreateOptions.DefaultTaxRates = new List<string>(1) 
-                { 
-                    taxRate.Id 
-                };
             }
 
             if (additionalStorageGb > 0)