diff --git a/app/components/form/fields/NameField.tsx b/app/components/form/fields/NameField.tsx
index a8fa6d1e16..b369f4db98 100644
--- a/app/components/form/fields/NameField.tsx
+++ b/app/components/form/fields/NameField.tsx
@@ -30,6 +30,12 @@ export function NameField<
       required={required}
       label={label}
       name={name}
+      transform={(value) =>
+        value
+          .toLowerCase()
+          .replace(/[\s_]+/g, '-')
+          .replace(/[^a-z0-9-]/g, '')
+      }
       {...textFieldProps}
     />
   )
diff --git a/app/components/form/fields/TextField.tsx b/app/components/form/fields/TextField.tsx
index 9163a02e48..46b2f41c22 100644
--- a/app/components/form/fields/TextField.tsx
+++ b/app/components/form/fields/TextField.tsx
@@ -47,7 +47,7 @@ export interface TextFieldProps<
   validate?: Validate<FieldPathValue<TFieldValues, TName>, TFieldValues>
   control: Control<TFieldValues>
   /** Alters the value of the input during the field's onChange event. */
-  transform?: (value: string) => FieldPathValue<TFieldValues, TName>
+  transform?: (value: string) => string
 }
 
 export function TextField<
diff --git a/app/forms/network-interface-create.tsx b/app/forms/network-interface-create.tsx
index 43a93b9414..e224016a8b 100644
--- a/app/forms/network-interface-create.tsx
+++ b/app/forms/network-interface-create.tsx
@@ -7,6 +7,7 @@
  */
 import { useMemo } from 'react'
 import { useForm } from 'react-hook-form'
+import type { SetRequired } from 'type-fest'
 
 import { useApiQuery, type ApiError, type InstanceNetworkInterfaceCreate } from '@oxide/api'
 
@@ -19,10 +20,10 @@ import { SideModalForm } from '~/components/form/SideModalForm'
 import { useProjectSelector } from '~/hooks/use-params'
 import { FormDivider } from '~/ui/lib/Divider'
 
-const defaultValues: InstanceNetworkInterfaceCreate = {
+const defaultValues: SetRequired<InstanceNetworkInterfaceCreate, 'ip'> = {
   name: '',
   description: '',
-  ip: undefined,
+  ip: '',
   subnetName: '',
   vpcName: '',
 }
@@ -58,7 +59,7 @@ export function CreateNetworkInterfaceForm({
       resourceName="network interface"
       title="Add network interface"
       onDismiss={onDismiss}
-      onSubmit={onSubmit}
+      onSubmit={({ ip, ...rest }) => onSubmit({ ip: ip.trim() || undefined, ...rest })}
       loading={loading}
       submitError={submitError}
     >
@@ -81,12 +82,7 @@ export function CreateNetworkInterfaceForm({
         required
         control={form.control}
       />
-      <TextField
-        name="ip"
-        label="IP Address"
-        control={form.control}
-        transform={(ip) => (ip.trim() === '' ? undefined : ip)}
-      />
+      <TextField name="ip" label="IP Address" control={form.control} />
     </SideModalForm>
   )
 }
diff --git a/test/e2e/project-create.e2e.ts b/test/e2e/project-create.e2e.ts
index 6db69b6682..944c57a607 100644
--- a/test/e2e/project-create.e2e.ts
+++ b/test/e2e/project-create.e2e.ts
@@ -30,13 +30,15 @@ test.describe('Project create', () => {
   })
 
   test('shows field-level validation error and does not POST', async ({ page }) => {
-    await page.fill('role=textbox[name="Name"]', 'Invalid name')
-
+    const input = page.getByRole('textbox', { name: 'Name' })
+    await input.pressSequentially('no sPoNgEbOb_CaSe or spaces')
+    await expect(input).toHaveValue('no-spongebob-case-or-spaces')
+    await input.fill('no-ending-dash-')
     // submit to trigger validation
     await page.getByRole('button', { name: 'Create project' }).click()
 
     await expect(
-      page.getByText('Can only contain lower-case letters, numbers, and dashes').nth(0)
+      page.getByText('Must end with a letter or number', { exact: true }).nth(0)
     ).toBeVisible()
   })