diff --git a/app/assets/tailwind/application.css b/app/assets/tailwind/application.css
index a3a9bf10..612baa8a 100644
--- a/app/assets/tailwind/application.css
+++ b/app/assets/tailwind/application.css
@@ -66,10 +66,14 @@
   box-shadow: 0 0 0 4px rgba(59, 130, 246, 0.1);
 }
 
-.input-field:hover:not(:focus) {
+.input-field:hover:not(:focus):not(:disabled) {
   @apply border-gray-400;
 }
 
+.input-field:disabled {
+  @apply bg-gray-100 text-gray-500;
+}
+
 .select-field {
   @apply w-full border border-gray-300 rounded-lg text-sm bg-white transition-all duration-200 cursor-pointer;
   padding: 0.625rem 2.5rem 0.625rem 0.875rem;
diff --git a/app/models/provider.rb b/app/models/provider.rb
index 2a448d8e..77b3f4f3 100644
--- a/app/models/provider.rb
+++ b/app/models/provider.rb
@@ -26,4 +26,21 @@ class Provider < ApplicationRecord
 
   validates :name, :provider_type, presence: true
   validates :name, uniqueness: true
+
+  validate :file_name_prefix_may_be_changed, on: :update, if: :file_name_prefix_changed?
+
+  def has_topics?
+    topics.any?
+  end
+
+  private
+
+  def file_name_prefix_may_be_changed
+    if has_topics?
+      errors.add(
+        :file_name_prefix,
+        "can't be changed as provider has associated topics and so file names are established"
+      )
+    end
+  end
 end
diff --git a/app/views/providers/_form.html.erb b/app/views/providers/_form.html.erb
index ee97b2f2..7adf123f 100644
--- a/app/views/providers/_form.html.erb
+++ b/app/views/providers/_form.html.erb
@@ -2,6 +2,25 @@
   <div class="space-y-6">
     <%= render "shared/errors", errors: provider.errors.full_messages, resource_name: provider.class.name %>
 
+    <!-- File name prefix uneditable notice -->
+    <% if @provider.has_topics? %>
+      <div id="file-name-prefix-uneditable-notice" class="bg-blue-50 border border-blue-200 rounded-lg p-4">
+        <div class="flex">
+          <div class="flex-shrink-0">
+            <svg class="h-5 w-5 text-blue-400" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+              <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M13 16h-1v-4h-1m1-4h.01M21 12a9 9 0 11-18 0 9 9 0 0118 0z"/>
+            </svg>
+          </div>
+          <div class="ml-3">
+            <p class="text-sm text-blue-700 m-0">
+              There are topics associated with this provider, so the file names are established and the file name prefix can't be edited.
+            </p>
+          </div>
+        </div>
+      </div>
+    <% end %>
+
+
     <div class="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-6">
 
       <!-- Provider Name -->
@@ -11,7 +30,7 @@
           <span class="text-red-500">*</span>
         <% end %>
         <%= form.text_field :name,
-            placeholder: "Enter provider name (e.g., Johns Hopkins, Mayo Clinic)",
+            placeholder: "e.g., Johns Hopkins, Mayo Clinic",
             autofocus: true,
             class: "input-field bg-gray-50" %>
         <p class="help-text">The official name of the healthcare provider or organization.</p>
@@ -29,6 +48,31 @@
         <p class="help-text">The type or category of healthcare provider.</p>
       </div>
 
+      <!-- File name prefix -->
+      <% if @provider.has_topics? %>
+        <div>
+          <%= form.label :file_name_prefix, class: "input-label" do %>
+            File name prefix
+          <% end %>
+          <%= form.text_field :file_name_prefix,
+              disabled: true,
+              value: @provider.file_name_prefix,
+              class: "input-field bg-gray-50"
+          %>
+          <p class="help-text">The prefix to use for this provider's uploads.</p>
+        </div>
+      <% else %>
+        <div>
+          <%= form.label :file_name_prefix, class: "input-label" do %>
+            File name prefix
+          <% end %>
+          <%= form.text_field :file_name_prefix,
+              placeholder: "e.g., 123_who_guidelines",
+              class: "input-field bg-gray-50" %>
+          <p class="help-text">The prefix to use for this provider's uploads.</p>
+        </div>
+      <% end %>
+
       <!-- Regions -->
       <div>
         <%= form.label :region, class: "input-label" do %>
diff --git a/app/views/providers/show.html.erb b/app/views/providers/show.html.erb
index dedc45ad..1b63629a 100644
--- a/app/views/providers/show.html.erb
+++ b/app/views/providers/show.html.erb
@@ -81,7 +81,7 @@
           </div>
 
           <div class="card-body">
-            <div class="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-8">
+            <div class="grid grid-cols-1 md:grid-cols-2 gap-8">
 
               <div>
                 <label class="input-label">Provider Name</label>
@@ -97,7 +97,7 @@
                 </div>
               </div>
 
-              <div>
+              <div class="col-span-full">
                 <label class="input-label">File Name Prefix</label>
                 <div class="bg-gray-50 p-4 rounded-lg border border-gray-200">
                   <% if @provider.file_name_prefix.present? %>
diff --git a/spec/jobs/documents_sync_job_spec.rb b/spec/jobs/documents_sync_job_spec.rb
index 46df0943..a0cf804a 100644
--- a/spec/jobs/documents_sync_job_spec.rb
+++ b/spec/jobs/documents_sync_job_spec.rb
@@ -1,13 +1,11 @@
 require "rails_helper"
 
 RSpec.describe DocumentsSyncJob, type: :job do
-  let(:topic) { create(:topic, :with_documents) }
-  let(:provider) { topic.provider }
+  let(:provider) { create(:provider, file_name_prefix: "MyPrefix") }
+  let(:topic) { create(:topic, :with_documents, provider:) }
   let(:document) { topic.documents.first }
   let(:file_name) { document.filename }
 
-  before { provider.update(file_name_prefix: "MyPrefix") }
-
   describe "#perform" do
     let(:file_worker) { instance_double(FileWorker) }
 
diff --git a/spec/models/provider_spec.rb b/spec/models/provider_spec.rb
new file mode 100644
index 00000000..1d828318
--- /dev/null
+++ b/spec/models/provider_spec.rb
@@ -0,0 +1,66 @@
+# == Schema Information
+#
+# Table name: providers
+# Database name: primary
+#
+#  id               :bigint           not null, primary key
+#  file_name_prefix :string
+#  name             :string
+#  provider_type    :string
+#  created_at       :datetime         not null
+#  updated_at       :datetime         not null
+#  old_id           :integer
+#
+# Indexes
+#
+#  index_providers_on_old_id  (old_id) UNIQUE
+#
+require "rails_helper"
+
+RSpec.describe Provider, type: :model do
+  let(:provider) { create(:provider) }
+  subject { provider }
+
+  describe "validations" do
+    it { should validate_presence_of(:provider_type) }
+    it { should validate_presence_of(:name) }
+    it { should validate_uniqueness_of(:name) }
+
+    describe "#file_name_prefix_may_be_changed" do
+      context "when a provider has topics" do
+        let!(:topic) { create(:topic, provider: provider) }
+
+        it "returns an error" do
+          provider.file_name_prefix = "updated_prefix"
+          expect(provider).not_to be_valid
+          expect(provider.errors[:file_name_prefix]).to match_array(
+            "can't be changed as provider has associated topics and so file names are established"
+          )
+        end
+      end
+
+      context "when a provider has no topics" do
+        it "does not return an error" do
+          provider.file_name_prefix = "updated_prefix"
+          expect(provider).to be_valid
+        end
+      end
+    end
+  end
+
+  describe "#has_topics?" do
+    context "when a provider has topics" do
+      let!(:topic) { create(:topic, provider: provider) }
+
+      it "returns true" do
+        expect(provider.has_topics?).to be true
+      end
+    end
+
+    context "when a provider has no topics" do
+      it "returns false" do
+        expect(provider.has_topics?).to be false
+      end
+    end
+  end
+end
diff --git a/spec/views/providers/edit.html.erb_spec.rb b/spec/views/providers/edit.html.erb_spec.rb
index fc4bf133..b49834f3 100644
--- a/spec/views/providers/edit.html.erb_spec.rb
+++ b/spec/views/providers/edit.html.erb_spec.rb
@@ -16,4 +16,28 @@
       assert_select "input[type='submit'][value='Update Provider']"
     end
   end
+
+  context "when the provider has associated topics" do
+    before { create(:topic, provider: provider) }
+
+    it "tells the user that the File name prefix can't be changed" do
+      render
+
+      assert_select "form[action=?][method=?]", provider_path(provider), "post" do
+        assert_select "input[name=?][disabled]", "provider[file_name_prefix]"
+      end
+
+      assert_select "div#file-name-prefix-uneditable-notice"
+    end
+  end
+
+  context "when the provider that has no associated topics" do
+    it "has the File name prefix field" do
+      render
+
+      assert_select "form[action=?][method=?]", provider_path(provider), "post" do
+        assert_select "input[name=?]", "provider[file_name_prefix]"
+      end
+    end
+  end
 end
diff --git a/spec/views/providers/new.html.erb_spec.rb b/spec/views/providers/new.html.erb_spec.rb
index 0088e81e..ab48436a 100644
--- a/spec/views/providers/new.html.erb_spec.rb
+++ b/spec/views/providers/new.html.erb_spec.rb
@@ -14,6 +14,7 @@
     assert_select "form[action=?][method=?]", providers_path, "post" do
       assert_select "input[name=?]", "provider[name]"
       assert_select "input[name=?]", "provider[provider_type]"
+      assert_select "input[name=?]", "provider[file_name_prefix]"
       assert_select "input[type='submit'][value='Create Provider']"
     end
   end