diff --git a/app/models/lookup/firm.rb b/app/models/lookup/firm.rb
index 73cdb77cf..a36c0edc4 100644
--- a/app/models/lookup/firm.rb
+++ b/app/models/lookup/firm.rb
@@ -3,7 +3,7 @@ class Firm < ApplicationRecord
     has_many :subsidiaries, primary_key: :fca_number, foreign_key: :fca_number
 
     validates :fca_number,
-              length: { is: 6 },
+              length: { in: 6..7 },
               numericality: { only_integer: true }
 
     def subsidiaries?
diff --git a/app/models/lookup/subsidiary.rb b/app/models/lookup/subsidiary.rb
index bb3ffdbe8..58b84bddc 100644
--- a/app/models/lookup/subsidiary.rb
+++ b/app/models/lookup/subsidiary.rb
@@ -1,7 +1,7 @@
 module Lookup
   class Subsidiary < ApplicationRecord
     validates :fca_number,
-              length: { is: 6 },
+              length: { in: 6..7 },
               numericality: { only_integer: true }
 
     def self.table_name
diff --git a/app/models/principal.rb b/app/models/principal.rb
index b67b57ba1..fb42f67b3 100644
--- a/app/models/principal.rb
+++ b/app/models/principal.rb
@@ -25,7 +25,7 @@ class Principal < ApplicationRecord
   validates :fca_number,
             presence: true,
             uniqueness: true,
-            length: { is: 6 },
+            length: { in: 6..7 },
             numericality: { only_integer: true }
 
   validates :email_address,
diff --git a/spec/models/lookup/firm_spec.rb b/spec/models/lookup/firm_spec.rb
index f8c8b0958..ae7ce0d65 100644
--- a/spec/models/lookup/firm_spec.rb
+++ b/spec/models/lookup/firm_spec.rb
@@ -11,8 +11,9 @@
         expect(described_class.new(fca_number: '123A45')).to_not be_valid
       end
 
-      it 'accepts only 6 digits' do
-        expect(described_class.new(fca_number: 1_234_567)).to_not be_valid
+      it 'accepts between 6 and 7 digits' do
+        expect(described_class.new(fca_number: 1_234_567)).to be_valid
+        expect(described_class.new(fca_number: 1_234_567_8)).to_not be_valid
       end
     end
   end