diff --git a/app/models/budget/ballot.rb b/app/models/budget/ballot.rb
index 074bf6a8f..399982d8e 100644
--- a/app/models/budget/ballot.rb
+++ b/app/models/budget/ballot.rb
@@ -64,8 +64,9 @@ class Budget
       @voting_style ||= voting_style_class.new(self)
     end
     delegate :amount_available, :amount_available_info, :amount_spent, :amount_spent_info,
-             :amount_limit_info, :change_vote_info, :enough_money?, :formatted_amount_available,
-             :formatted_amount_limit, :formatted_amount_spent, :voted_info,
+             :amount_limit_info, :change_vote_info, :enough_resources?, :formatted_amount_available,
+             :formatted_amount_limit, :formatted_amount_spent, :not_enough_resources_error,
+             :reason_for_not_being_ballotable, :voted_info,
              to: :voting_style
 
     private
diff --git a/app/models/budget/ballot/line.rb b/app/models/budget/ballot/line.rb
index 9d9805781..58078de98 100644
--- a/app/models/budget/ballot/line.rb
+++ b/app/models/budget/ballot/line.rb
@@ -10,7 +10,7 @@ class Budget
       validates :ballot_id, :investment_id, :heading_id, :group_id, :budget_id, presence: true
 
       validate :check_selected
-      validate :check_sufficient_funds
+      validate :check_enough_resources
       validate :check_valid_heading
 
       scope :by_investment, ->(investment_id) { where(investment_id: investment_id) }
@@ -18,9 +18,12 @@ class Budget
       before_validation :set_denormalized_ids
       after_save :store_user_heading
 
-      def check_sufficient_funds
+      def check_enough_resources
         ballot.lock!
-        errors.add(:money, "insufficient funds") unless ballot.enough_money?(investment)
+
+        unless ballot.enough_resources?(investment)
+          errors.add(:resources, ballot.not_enough_resources_error)
+        end
       end
 
       def check_valid_heading
diff --git a/app/models/budget/investment.rb b/app/models/budget/investment.rb
index 63f03441a..4adf23556 100644
--- a/app/models/budget/investment.rb
+++ b/app/models/budget/investment.rb
@@ -268,8 +268,9 @@ class Budget
       return :not_selected               unless selected?
       return :no_ballots_allowed         unless budget.balloting?
       return :different_heading_assigned unless ballot.valid_heading?(heading)
-      return :not_enough_money           unless ballot.enough_money?(self)
       return :casted_offline             if ballot.casted_offline?
+
+      ballot.reason_for_not_being_ballotable(self)
     end
 
     def permission_problem(user)
diff --git a/app/models/budget/voting_styles/knapsack.rb b/app/models/budget/voting_styles/knapsack.rb
index 815a19102..4f2c72a19 100644
--- a/app/models/budget/voting_styles/knapsack.rb
+++ b/app/models/budget/voting_styles/knapsack.rb
@@ -1,8 +1,16 @@
 class Budget::VotingStyles::Knapsack < Budget::VotingStyles::Base
-  def enough_money?(investment)
+  def enough_resources?(investment)
     investment.price.to_i <= amount_available(investment.heading)
   end
 
+  def reason_for_not_being_ballotable(investment)
+    :not_enough_money unless enough_resources?(investment)
+  end
+
+  def not_enough_resources_error
+    "insufficient funds"
+  end
+
   def amount_available(heading)
     amount_limit(heading) - amount_spent(heading)
   end