diff --git a/packages/shared/src/schemas/account.schema.ts b/packages/shared/src/schemas/account.schema.ts
index 0f991ae..8eee5ea 100644
--- a/packages/shared/src/schemas/account.schema.ts
+++ b/packages/shared/src/schemas/account.schema.ts
@@ -1,5 +1,10 @@
 import { z } from 'zod'
 
+/** Coerce empty strings to undefined — solves HTML form inputs sending '' for blank optional fields */
+function opt<T extends z.ZodTypeAny>(schema: T) {
+  return z.preprocess((v) => (v === '' ? undefined : v), schema.optional()) as z.ZodEffects<z.ZodOptional<T>>
+}
+
 export const BillingMode = z.enum(['consolidated', 'split'])
 export type BillingMode = z.infer<typeof BillingMode>
 
@@ -11,8 +16,8 @@ export type TaxExemptStatus = z.infer<typeof TaxExemptStatus>
 
 export const AccountCreateSchema = z.object({
   name: z.string().min(1).max(255),
-  email: z.string().email().optional(),
-  phone: z.string().max(50).optional(),
+  email: opt(z.string().email()),
+  phone: opt(z.string().max(50)),
   address: z
     .object({
       street: z.string().optional(),
@@ -22,7 +27,7 @@ export const AccountCreateSchema = z.object({
     })
     .optional(),
   billingMode: BillingMode.default('consolidated'),
-  notes: z.string().optional(),
+  notes: opt(z.string()),
 })
 export type AccountCreateInput = z.infer<typeof AccountCreateSchema>
 
@@ -33,11 +38,11 @@ export const MemberCreateSchema = z.object({
   accountId: z.string().uuid(),
   firstName: z.string().min(1).max(100),
   lastName: z.string().min(1).max(100),
-  dateOfBirth: z.string().date().optional(),
+  dateOfBirth: opt(z.string().date()),
   isMinor: z.boolean().optional(),
-  email: z.string().email().optional(),
-  phone: z.string().max(50).optional(),
-  notes: z.string().optional(),
+  email: opt(z.string().email()),
+  phone: opt(z.string().max(50)),
+  notes: opt(z.string()),
 })
 export type MemberCreateInput = z.infer<typeof MemberCreateSchema>
 
@@ -56,14 +61,14 @@ export type IdentifierType = z.infer<typeof IdentifierType>
 export const MemberIdentifierCreateSchema = z.object({
   memberId: z.string().uuid(),
   type: IdentifierType,
-  label: z.string().max(100).optional(),
+  label: opt(z.string().max(100)),
   value: z.string().min(1).max(255),
-  issuingAuthority: z.string().max(255).optional(),
-  issuedDate: z.string().date().optional(),
-  expiresAt: z.string().date().optional(),
-  imageFrontUrl: z.string().max(500).optional(),
-  imageBackUrl: z.string().max(500).optional(),
-  notes: z.string().optional(),
+  issuingAuthority: opt(z.string().max(255)),
+  issuedDate: opt(z.string().date()),
+  expiresAt: opt(z.string().date()),
+  imageFront: opt(z.string()),
+  imageBack: opt(z.string()),
+  notes: opt(z.string()),
   isPrimary: z.boolean().default(false),
 })
 export type MemberIdentifierCreateInput = z.infer<typeof MemberIdentifierCreateSchema>
@@ -91,8 +96,8 @@ export const PaymentMethodCreateSchema = z.object({
   accountId: z.string().uuid(),
   processor: PaymentProcessor,
   processorPaymentMethodId: z.string().min(1).max(255),
-  cardBrand: z.string().max(50).optional(),
-  lastFour: z.string().length(4).optional(),
+  cardBrand: opt(z.string().max(50)),
+  lastFour: opt(z.string().length(4)),
   expMonth: z.number().int().min(1).max(12).optional(),
   expYear: z.number().int().min(2000).max(2100).optional(),
   isDefault: z.boolean().default(false),
@@ -110,19 +115,19 @@ export type PaymentMethodUpdateInput = z.infer<typeof PaymentMethodUpdateSchema>
 export const TaxExemptionCreateSchema = z.object({
   accountId: z.string().uuid(),
   certificateNumber: z.string().min(1).max(255),
-  certificateType: z.string().max(100).optional(),
-  issuingState: z.string().length(2).optional(),
-  expiresAt: z.string().date().optional(),
-  notes: z.string().optional(),
+  certificateType: opt(z.string().max(100)),
+  issuingState: opt(z.string().length(2)),
+  expiresAt: opt(z.string().date()),
+  notes: opt(z.string()),
 })
 export type TaxExemptionCreateInput = z.infer<typeof TaxExemptionCreateSchema>
 
 export const TaxExemptionUpdateSchema = z.object({
-  certificateNumber: z.string().min(1).max(255).optional(),
-  certificateType: z.string().max(100).optional(),
-  issuingState: z.string().length(2).optional(),
-  expiresAt: z.string().date().optional(),
-  notes: z.string().optional(),
+  certificateNumber: opt(z.string().min(1).max(255)),
+  certificateType: opt(z.string().max(100)),
+  issuingState: opt(z.string().length(2)),
+  expiresAt: opt(z.string().date()),
+  notes: opt(z.string()),
 })
 export type TaxExemptionUpdateInput = z.infer<typeof TaxExemptionUpdateSchema>
 
@@ -131,14 +136,14 @@ export type TaxExemptionUpdateInput = z.infer<typeof TaxExemptionUpdateSchema>
 export const LookupCreateSchema = z.object({
   name: z.string().min(1).max(100),
   slug: z.string().min(1).max(100).regex(/^[a-z0-9_]+$/, 'Slug must be lowercase alphanumeric with underscores'),
-  description: z.string().optional(),
+  description: opt(z.string()),
   sortOrder: z.number().int().default(0),
 })
 export type LookupCreateInput = z.infer<typeof LookupCreateSchema>
 
 export const LookupUpdateSchema = z.object({
-  name: z.string().min(1).max(100).optional(),
-  description: z.string().optional(),
+  name: opt(z.string().min(1).max(100)),
+  description: opt(z.string()),
   sortOrder: z.number().int().optional(),
   isActive: z.boolean().optional(),
 })
diff --git a/packages/shared/src/schemas/inventory.schema.ts b/packages/shared/src/schemas/inventory.schema.ts
index 168ed36..96d882b 100644
--- a/packages/shared/src/schemas/inventory.schema.ts
+++ b/packages/shared/src/schemas/inventory.schema.ts
@@ -1,9 +1,14 @@
 import { z } from 'zod'
 
+/** Coerce empty strings to undefined — solves HTML form inputs sending '' for blank optional fields */
+function opt<T extends z.ZodTypeAny>(schema: T) {
+  return z.preprocess((v) => (v === '' ? undefined : v), schema.optional()) as z.ZodEffects<z.ZodOptional<T>>
+}
+
 export const CategoryCreateSchema = z.object({
   name: z.string().min(1).max(255),
-  description: z.string().optional(),
-  parentId: z.string().uuid().optional(),
+  description: opt(z.string()),
+  parentId: opt(z.string().uuid()),
   sortOrder: z.number().int().default(0),
 })
 export type CategoryCreateInput = z.infer<typeof CategoryCreateSchema>
@@ -13,13 +18,13 @@ export type CategoryUpdateInput = z.infer<typeof CategoryUpdateSchema>
 
 export const SupplierCreateSchema = z.object({
   name: z.string().min(1).max(255),
-  contactName: z.string().max(255).optional(),
-  email: z.string().email().optional(),
-  phone: z.string().max(50).optional(),
-  website: z.string().max(255).optional(),
-  accountNumber: z.string().max(100).optional(),
-  paymentTerms: z.string().max(100).optional(),
-  notes: z.string().optional(),
+  contactName: opt(z.string().max(255)),
+  email: opt(z.string().email()),
+  phone: opt(z.string().max(50)),
+  website: opt(z.string().max(255)),
+  accountNumber: opt(z.string().max(100)),
+  paymentTerms: opt(z.string().max(100)),
+  notes: opt(z.string()),
 })
 export type SupplierCreateInput = z.infer<typeof SupplierCreateSchema>
 
@@ -45,14 +50,14 @@ export const ItemCondition = z.string().min(1).max(100)
 export const UnitStatus = z.string().min(1).max(100)
 
 export const ProductCreateSchema = z.object({
-  sku: z.string().max(100).optional(),
-  upc: z.string().max(100).optional(),
+  sku: opt(z.string().max(100)),
+  upc: opt(z.string().max(100)),
   name: z.string().min(1).max(255),
-  description: z.string().optional(),
-  brand: z.string().max(255).optional(),
-  model: z.string().max(255).optional(),
-  categoryId: z.string().uuid().optional(),
-  locationId: z.string().uuid().optional(),
+  description: opt(z.string()),
+  brand: opt(z.string().max(255)),
+  model: opt(z.string().max(255)),
+  categoryId: opt(z.string().uuid()),
+  locationId: opt(z.string().uuid()),
   isSerialized: z.boolean().default(false),
   isRental: z.boolean().default(false),
   isDualUseRepair: z.boolean().default(false),
@@ -73,13 +78,13 @@ export const ProductSearchSchema = z.object({
 
 export const InventoryUnitCreateSchema = z.object({
   productId: z.string().uuid(),
-  locationId: z.string().uuid().optional(),
-  serialNumber: z.string().max(255).optional(),
+  locationId: opt(z.string().uuid()),
+  serialNumber: opt(z.string().max(255)),
   condition: ItemCondition.default('new'),
   status: UnitStatus.default('available'),
-  purchaseDate: z.string().date().optional(),
+  purchaseDate: opt(z.string().date()),
   purchaseCost: z.number().min(0).optional(),
-  notes: z.string().optional(),
+  notes: opt(z.string()),
 })
 export type InventoryUnitCreateInput = z.infer<typeof InventoryUnitCreateSchema>