diff --git a/apps/api/src/server.ts b/apps/api/src/server.ts
index 98df40b..166ccd9 100644
--- a/apps/api/src/server.ts
+++ b/apps/api/src/server.ts
@@ -563,6 +563,10 @@ export const app = new Elysia()
                 params: t.Object({ id: t.String() })
             })
             .post("/:id/request-action", async ({ params: { id }, body: { reviewerNotes, activityVerifications } }) => {
+                const verification = await s.Verifications.get(id);
+                if (!verification) throw new NotFoundError("Verification not found");
+                if (verification.status === "completed") throw status(409, { error: "Cannot modify a completed verification" });
+
                 const updated = await s.Verifications.requestAction(id, reviewerNotes ?? null, activityVerifications);
                 if (!updated) throw new NotFoundError("Verification not found");
             }, {
@@ -573,6 +577,10 @@ export const app = new Elysia()
                 })
             })
             .post("/:id/complete", async ({ params: { id }, body: { activityVerifications }, accountId }) => {
+                const verification = await s.Verifications.get(id);
+                if (!verification) throw new NotFoundError("Verification not found");
+                if (verification.status === "completed") throw status(409, { error: "Cannot modify a completed verification" });
+
                 const updated = await s.Verifications.complete(id, accountId, activityVerifications);
                 if (!updated) throw new NotFoundError("Verification not found");
             }, {
diff --git a/apps/portal/src/routes/(app)/verification/requests/[id]/+page.svelte b/apps/portal/src/routes/(app)/verification/requests/[id]/+page.svelte
index 3b1b9c4..60e9c12 100644
--- a/apps/portal/src/routes/(app)/verification/requests/[id]/+page.svelte
+++ b/apps/portal/src/routes/(app)/verification/requests/[id]/+page.svelte
@@ -120,6 +120,7 @@
         ACTIVITIES.filter((a) => verf[a] !== "unset").length,
     );
     const allReviewed = $derived(reviewedCount === ACTIVITIES.length);
+    const isReadOnly = $derived(verification?.status === "completed");
 
     async function load() {
         loading = true;
@@ -152,6 +153,7 @@
     }
 
     function setVerf(activity: Activity, choice: VerfChoice) {
+        if (isReadOnly) return;
         verf[activity] = choice;
     }
 
@@ -290,6 +292,7 @@
                     class="btn btn-sm {verf[activity] === 'pass'
                         ? 'btn-success'
                         : 'btn-outline btn-success'}"
+                    disabled={isReadOnly}
                     onclick={() => setVerf(activity, "pass")}
                 >
                     Pass
@@ -298,13 +301,14 @@
                     class="btn btn-sm {verf[activity] === 'fail'
                         ? 'btn-error'
                         : 'btn-outline btn-error'}"
+                    disabled={isReadOnly}
                     onclick={() => setVerf(activity, "fail")}
                 >
                     Fail
                 </button>
                 <button
                     class="btn btn-sm btn-ghost"
-                    disabled={verf[activity] === "unset"}
+                    disabled={isReadOnly || verf[activity] === "unset"}
                     onclick={() => setVerf(activity, "unset")}
                 >
                     Clear
@@ -396,6 +400,7 @@
                     class="textarea textarea-bordered w-full"
                     rows="3"
                     placeholder="What needs to be fixed?"
+                    disabled={isReadOnly}
                     bind:value={notes}
                 ></textarea>
             </label>
@@ -415,31 +420,37 @@
                     &larr; Previous
                 </button>
 
-                <div class="flex items-center gap-2">
-                    {#if !allReviewed}
-                        <span class="text-xs text-warning"
-                            >Mark every activity Pass or Fail to complete</span
+                {#if isReadOnly}
+                    <span class="text-sm opacity-70"
+                        >This verification is completed and read-only.</span
+                    >
+                {:else}
+                    <div class="flex items-center gap-2">
+                        {#if !allReviewed}
+                            <span class="text-xs text-warning"
+                                >Mark every activity Pass or Fail to complete</span
+                            >
+                        {/if}
+                        <button
+                            class="btn btn-warning"
+                            disabled={!!submitting}
+                            onclick={requestAction}
                         >
-                    {/if}
-                    <button
-                        class="btn btn-warning"
-                        disabled={!!submitting}
-                        onclick={requestAction}
-                    >
-                        {submitting === "action"
-                            ? "Submitting..."
-                            : "Request action"}
-                    </button>
-                    <button
-                        class="btn btn-success"
-                        disabled={!!submitting || !allReviewed}
-                        onclick={complete}
-                    >
-                        {submitting === "complete"
-                            ? "Submitting..."
-                            : "Complete"}
-                    </button>
-                </div>
+                            {submitting === "action"
+                                ? "Submitting..."
+                                : "Request action"}
+                        </button>
+                        <button
+                            class="btn btn-success"
+                            disabled={!!submitting || !allReviewed}
+                            onclick={complete}
+                        >
+                            {submitting === "complete"
+                                ? "Submitting..."
+                                : "Complete"}
+                        </button>
+                    </div>
+                {/if}
             </div>
         </div>
     {/if}