diff --git a/packages/ui/primitives/document-flow/add-signers.tsx b/packages/ui/primitives/document-flow/add-signers.tsx
index 412fbfc19..9e40759b4 100644
--- a/packages/ui/primitives/document-flow/add-signers.tsx
+++ b/packages/ui/primitives/document-flow/add-signers.tsx
@@ -126,12 +126,12 @@ export const AddSignersFormPartial = ({
           <AnimatePresence>
             {signers.map((signer, index) => (
               <motion.div
-                key={signer.formId}
+                key={signer.id}
                 data-native-id={signer.nativeId}
                 className="flex flex-wrap items-end gap-x-4"
               >
                 <div className="flex-1">
-                  <Label htmlFor={`signer-${signer.formId}-email`}>
+                  <Label htmlFor={`signer-${signer.id}-email`}>
                     Email
                     <span className="text-destructive ml-1 inline-block font-medium">*</span>
                   </Label>
@@ -141,7 +141,7 @@ export const AddSignersFormPartial = ({
                     name={`signers.${index}.email`}
                     render={({ field }) => (
                       <Input
-                        id={`signer-${signer.formId}-email`}
+                        id={`signer-${signer.id}-email`}
                         type="email"
                         className="bg-background mt-2"
                         disabled={isSubmitting || hasBeenSentToRecipientId(signer.nativeId)}
@@ -153,14 +153,14 @@ export const AddSignersFormPartial = ({
                 </div>
 
                 <div className="flex-1">
-                  <Label htmlFor={`signer-${signer.formId}-name`}>Name</Label>
+                  <Label htmlFor={`signer-${signer.id}-name`}>Name</Label>
 
                   <Controller
                     control={control}
                     name={`signers.${index}.name`}
                     render={({ field }) => (
                       <Input
-                        id={`signer-${signer.formId}-name`}
+                        id={`signer-${signer.id}-name`}
                         type="text"
                         className="bg-background mt-2"
                         disabled={isSubmitting || hasBeenSentToRecipientId(signer.nativeId)}
@@ -195,7 +195,11 @@ export const AddSignersFormPartial = ({
           </AnimatePresence>
         </div>
 
-        <FormErrorMessage className="mt-2" error={errors.signers} />
+        <FormErrorMessage
+          className="mt-2"
+          // Dirty hack to handle errors when .root is populated for an array type
+          error={'signers__root' in errors && errors['signers__root']}
+        />
 
         <div className="mt-4">
           <Button type="button" disabled={isSubmitting} onClick={() => onAddSigner()}>
diff --git a/packages/ui/primitives/document-flow/add-signers.types.ts b/packages/ui/primitives/document-flow/add-signers.types.ts
index 2b1418934..3dabd67e5 100644
--- a/packages/ui/primitives/document-flow/add-signers.types.ts
+++ b/packages/ui/primitives/document-flow/add-signers.types.ts
@@ -1,19 +1,24 @@
 import { z } from 'zod';
 
-export const ZAddSignersFormSchema = z.object({
-  signers: z
-    .array(
+export const ZAddSignersFormSchema = z
+  .object({
+    signers: z.array(
       z.object({
         formId: z.string().min(1),
         nativeId: z.number().optional(),
         email: z.string().min(1).email(),
         name: z.string(),
       }),
-    )
-    .refine((signers) => {
-      const emails = signers.map((signer) => signer.email);
+    ),
+  })
+  .refine(
+    (schema) => {
+      const emails = schema.signers.map((signer) => signer.email.toLowerCase());
+
       return new Set(emails).size === emails.length;
-    }, 'Signers must have unique emails'),
-});
+    },
+    // Dirty hack to handle errors when .root is populated for an array type
+    { message: 'Signers must have unique emails', path: ['signers__root'] },
+  );
 
 export type TAddSignersFormSchema = z.infer<typeof ZAddSignersFormSchema>;
diff --git a/packages/ui/primitives/form/form-error-message.tsx b/packages/ui/primitives/form/form-error-message.tsx
index 6fa7c32b0..bb555b7f7 100644
--- a/packages/ui/primitives/form/form-error-message.tsx
+++ b/packages/ui/primitives/form/form-error-message.tsx
@@ -4,13 +4,17 @@ import { cn } from '@documenso/ui/lib/utils';
 
 export type FormErrorMessageProps = {
   className?: string;
-  error: { message?: string } | undefined;
+  error: { message?: string } | undefined | unknown;
+};
+
+const isErrorWithMessage = (error: unknown): error is { message?: string } => {
+  return typeof error === 'object' && error !== null && 'message' in error;
 };
 
 export const FormErrorMessage = ({ error, className }: FormErrorMessageProps) => {
   return (
     <AnimatePresence>
-      {error && (
+      {isErrorWithMessage(error) && (
         <motion.p
           initial={{
             opacity: 0,