diff --git a/dotnet-authserver/src/TeacherIdentity.AuthServer/Pages/Admin/MergeUser/SelectUser.cshtml b/dotnet-authserver/src/TeacherIdentity.AuthServer/Pages/Admin/MergeUser/SelectUser.cshtml
index 7d8f6c3b3..f05f6b3bd 100644
--- a/dotnet-authserver/src/TeacherIdentity.AuthServer/Pages/Admin/MergeUser/SelectUser.cshtml
+++ b/dotnet-authserver/src/TeacherIdentity.AuthServer/Pages/Admin/MergeUser/SelectUser.cshtml
@@ -5,35 +5,6 @@
     ViewBag.Title = Html.DisplayNameFor(m => m.UserIdToMerge);
 }
 
-@section Styles
-{
-    <link rel="stylesheet" href="~/Styles/Components/accessible-autocomplete.min.css" asp-append-version="true" />
-}
-
-@section Scripts
-{
-    <script src="~/Scripts/Components/accessible-autocomplete.min.js"></script>
-    <script asp-add-nonce="true">
-        window.onload = function () {
-            const inputName = '@nameof(Model.UserIdToMerge)';
-            const select = document.querySelector(`select[name=${inputName}`);
-            const value = select.value;
-            const container = select.parentElement;
-
-            accessibleAutocomplete({
-                element: container,
-                id: inputName,
-                source: @Html.Raw(Json.Serialize(Model.UserIds)),
-                defaultValue: value
-            })
-
-            container.removeChild(select);
-            const input = container.querySelector('input');
-            input.name = inputName;
-        }
-    </script>
-}
-
 @section BeforeContent {
     <govuk-back-link asp-page="/Admin/User" asp-route-userId="@Model.UserId" />
 }
@@ -41,18 +12,11 @@
 <div class="govuk-grid-row">
     <div class="govuk-grid-column-two-thirds-from-desktop">
         <form asp-page="MergeUser" asp-route-userId="@Model.UserId">
-            <govuk-select asp-for="UserIdToMerge">
-                <govuk-select-label is-page-heading="true" class="govuk-label--l">
+            <govuk-input asp-for="UserIdToMerge" input-class="govuk-input--width-20">
+                <govuk-input-label is-page-heading="true" class="govuk-label--l">
                     <h1 class="govuk-heading-l">@ViewBag.Title</h1>
-
-                    <p>Which user do you want to merge with <b>@Model.UserId</b>.</p>
-                </govuk-select-label>
-                <govuk-select-item value=""></govuk-select-item>
-                @foreach (var userId in Model.UserIds ?? Enumerable.Empty<Guid>())
-                {
-                    <govuk-select-item value="@userId">@userId</govuk-select-item>
-                }
-            </govuk-select>
+                </govuk-input-label>
+            </govuk-input>
 
             <govuk-button type="submit">Continue</govuk-button>
         </form>
diff --git a/dotnet-authserver/src/TeacherIdentity.AuthServer/Pages/Admin/MergeUser/SelectUser.cshtml.cs b/dotnet-authserver/src/TeacherIdentity.AuthServer/Pages/Admin/MergeUser/SelectUser.cshtml.cs
index 7d624c863..9300bf896 100644
--- a/dotnet-authserver/src/TeacherIdentity.AuthServer/Pages/Admin/MergeUser/SelectUser.cshtml.cs
+++ b/dotnet-authserver/src/TeacherIdentity.AuthServer/Pages/Admin/MergeUser/SelectUser.cshtml.cs
@@ -18,11 +18,9 @@ public Merge(TeacherIdentityServerDbContext dbContext)
         _dbContext = dbContext;
     }
 
-    public ICollection<Guid>? UserIds { get; set; }
-
     [BindProperty]
-    [Display(Name = "Select which user to merge")]
-    [Required(ErrorMessage = "Select which user you want to merge")]
+    [Display(Name = "Enter the user ID to merge")]
+    [Required(ErrorMessage = "Enter the user ID to merge")]
     public Guid? UserIdToMerge { get; set; }
 
     [FromRoute]
@@ -34,14 +32,17 @@ public void OnGet()
 
     public IActionResult OnPost()
     {
-        if (!ModelState.IsValid)
+        if (!UserIdToMerge.HasValue)
         {
-            return this.PageWithErrors();
+            ModelState.AddModelError(nameof(UserIdToMerge), "Enter the user ID of the user to merge.");
+        }
+        else if (UserIdToMerge.Value == UserId)
+        {
+            ModelState.AddModelError(nameof(UserIdToMerge), "User cannot be merged with itself.");
         }
 
-        if (UserIds == null || !UserIds.Contains((Guid)UserIdToMerge!))
+        if (!ModelState.IsValid)
         {
-            ModelState.AddModelError(nameof(UserIdToMerge), "You must select a user ID from the given list");
             return this.PageWithErrors();
         }
 
@@ -58,11 +59,6 @@ public override async Task OnPageHandlerExecutionAsync(PageHandlerExecutingConte
             return;
         }
 
-        UserIds = _dbContext.Users
-            .Where(u => u.UserId != UserId && u.UserType == UserType.Default)
-            .Select(u => u.UserId)
-            .ToArray();
-
         await next();
     }
 }
diff --git a/dotnet-authserver/tests/TeacherIdentity.AuthServer.Tests/EndpointTests/Admin/MergeUser/SelectUserTests.cs b/dotnet-authserver/tests/TeacherIdentity.AuthServer.Tests/EndpointTests/Admin/MergeUser/SelectUserTests.cs
index 6920ea884..1a84e491b 100644
--- a/dotnet-authserver/tests/TeacherIdentity.AuthServer.Tests/EndpointTests/Admin/MergeUser/SelectUserTests.cs
+++ b/dotnet-authserver/tests/TeacherIdentity.AuthServer.Tests/EndpointTests/Admin/MergeUser/SelectUserTests.cs
@@ -97,7 +97,7 @@ public async Task Post_EmptyUserIdToMerge_ReturnsError()
         var response = await HttpClient.SendAsync(request);
 
         // Assert
-        await AssertEx.HtmlResponseHasError(response, "UserIdToMerge", "Select which user you want to merge");
+        await AssertEx.HtmlResponseHasError(response, "UserIdToMerge", "Enter the user ID to merge");
     }
 
     [Fact]
@@ -105,13 +105,13 @@ public async Task Post_InvalidUserIdToMerge_ReturnsError()
     {
         // Arrange
         var user = await TestData.CreateUser(userType: UserType.Default, hasTrn: false);
-        var invalidUserToMerge = await TestData.CreateUser(userType: UserType.Staff, hasTrn: false);
+        var invalidUserToMergeId = user.UserId;
 
         var request = new HttpRequestMessage(HttpMethod.Post, $"/admin/users/{user.UserId}/merge")
         {
             Content = new FormUrlEncodedContentBuilder()
             {
-                { "UserIdToMerge", invalidUserToMerge.UserId }
+                { "UserIdToMerge", invalidUserToMergeId }
             }
         };
 
@@ -119,7 +119,7 @@ public async Task Post_InvalidUserIdToMerge_ReturnsError()
         var response = await HttpClient.SendAsync(request);
 
         // Assert
-        await AssertEx.HtmlResponseHasError(response, "UserIdToMerge", "You must select a user ID from the given list");
+        await AssertEx.HtmlResponseHasError(response, "UserIdToMerge", "User cannot be merged with itself.");
     }
 
     [Fact]