diff --git a/Elwig/Helpers/AppDbContext.cs b/Elwig/Helpers/AppDbContext.cs
index 30d9099..d3f9fdc 100644
--- a/Elwig/Helpers/AppDbContext.cs
+++ b/Elwig/Helpers/AppDbContext.cs
@@ -200,6 +200,13 @@ namespace Elwig.Helpers {
             return c + 1;
         }
 
+        public async Task<int> NextAvNr(int year) {
+            int c = 0;
+            (await PaymentVariants.Where(v => v.Year == year).Select(v => v.AvNr).ToListAsync())
+                .ForEach(a => { if (a <= c + 100) c = a; });
+            return c + 1;
+        }
+
         public async Task<WineQualLevel> GetWineQualityLevel(double kmw) {
             return await WineQualityLevels
                 .Where(q => !q.IsPredicate && (q.MinKmw == null || q.MinKmw <= kmw))