diff --git a/packages/billing/src/schema/create-billing-checkout.schema.ts b/packages/billing/src/schema/create-billing-checkout.schema.ts
index be476921a..22a85bdc5 100644
--- a/packages/billing/src/schema/create-billing-checkout.schema.ts
+++ b/packages/billing/src/schema/create-billing-checkout.schema.ts
@@ -5,7 +5,7 @@ import { LineItemUsageType, PaymentType } from '../create-billing-schema';
 export const CreateBillingCheckoutSchema = z
   .object({
     returnUrl: z.string().url(),
-    accountId: z.string(),
+    accountId: z.string().uuid(),
     paymentType: PaymentType,
     lineItems: z.array(
       z.object({
@@ -16,7 +16,7 @@ export const CreateBillingCheckoutSchema = z
     ),
     trialDays: z.number().optional(),
     customerId: z.string().optional(),
-    customerEmail: z.string().optional(),
+    customerEmail: z.string().email().optional(),
   })
   .refine(
     (schema) => {
diff --git a/packages/features/team-accounts/src/schema/leave-team-account.schema.ts b/packages/features/team-accounts/src/schema/leave-team-account.schema.ts
index 1ba4c6ce5..a9168cdae 100644
--- a/packages/features/team-accounts/src/schema/leave-team-account.schema.ts
+++ b/packages/features/team-accounts/src/schema/leave-team-account.schema.ts
@@ -1,6 +1,6 @@
 import { z } from 'zod';
 
 export const LeaveTeamAccountSchema = z.object({
-  accountId: z.string(),
+  accountId: z.string().uuid(),
   confirmation: z.custom((value) => value === 'LEAVE'),
 });
diff --git a/packages/features/team-accounts/src/schema/update-invitation-schema.ts b/packages/features/team-accounts/src/schema/update-invitation-schema.ts
index f833fdd55..4882695e9 100644
--- a/packages/features/team-accounts/src/schema/update-invitation-schema.ts
+++ b/packages/features/team-accounts/src/schema/update-invitation-schema.ts
@@ -1,8 +1,6 @@
 import { z } from 'zod';
 
-type Role = string;
-
 export const UpdateInvitationSchema = z.object({
   invitationId: z.number(),
-  role: z.custom<Role>(() => z.string().min(1)),
+  role: z.string().min(1),
 });
diff --git a/packages/features/team-accounts/src/server/services/leave-team-account.service.ts b/packages/features/team-accounts/src/server/services/leave-team-account.service.ts
index 059cdc1d8..a889eb68a 100644
--- a/packages/features/team-accounts/src/server/services/leave-team-account.service.ts
+++ b/packages/features/team-accounts/src/server/services/leave-team-account.service.ts
@@ -7,8 +7,8 @@ import { Logger } from '@kit/shared/logger';
 import { Database } from '@kit/supabase/database';
 
 const Schema = z.object({
-  accountId: z.string(),
-  userId: z.string(),
+  accountId: z.string().uuid(),
+  userId: z.string().uuid(),
 });
 
 export class LeaveTeamAccountService {
diff --git a/packages/mailers/src/schema/mailer.schema.ts b/packages/mailers/src/schema/mailer.schema.ts
index 4f77c3189..1fd1f5849 100644
--- a/packages/mailers/src/schema/mailer.schema.ts
+++ b/packages/mailers/src/schema/mailer.schema.ts
@@ -3,7 +3,9 @@ import { z } from 'zod';
 export const MailerSchema = z
   .object({
     to: z.string().email(),
-    from: z.string().email(),
+    // this is not necessarily formatted
+    // as an email so we type it loosely
+    from: z.string().min(1),
     subject: z.string(),
   })
   .and(
diff --git a/packages/stripe/src/components/stripe-embedded-checkout.tsx b/packages/stripe/src/components/stripe-embedded-checkout.tsx
index 6fcf3c093..722d256c7 100644
--- a/packages/stripe/src/components/stripe-embedded-checkout.tsx
+++ b/packages/stripe/src/components/stripe-embedded-checkout.tsx
@@ -2,7 +2,6 @@
 
 import { useState } from 'react';
 
-import { invariant } from '@epic-web/invariant';
 import {
   EmbeddedCheckout,
   EmbeddedCheckoutProvider,
@@ -16,11 +15,13 @@ import {
   DialogTitle,
 } from '@kit/ui/dialog';
 
-const STRIPE_PUBLISHABLE_KEY = process.env.NEXT_PUBLIC_STRIPE_PUBLISHABLE_KEY;
+import { StripeClientEnvSchema } from '../schema/stripe-client-env.schema';
 
-invariant(STRIPE_PUBLISHABLE_KEY, 'Stripe publishable key is required');
+const { publishableKey } = StripeClientEnvSchema.parse({
+  publishableKey: process.env.NEXT_PUBLIC_STRIPE_PUBLISHABLE_KEY,
+});
 
-const stripePromise = loadStripe(STRIPE_PUBLISHABLE_KEY);
+const stripePromise = loadStripe(publishableKey);
 
 export function StripeCheckout({
   checkoutToken,
diff --git a/packages/stripe/src/schema/stripe-client-env.schema.ts b/packages/stripe/src/schema/stripe-client-env.schema.ts
index c0fa90cf2..5cb12ee39 100644
--- a/packages/stripe/src/schema/stripe-client-env.schema.ts
+++ b/packages/stripe/src/schema/stripe-client-env.schema.ts
@@ -1,5 +1,15 @@
 import { z } from 'zod';
 
-export const StripeClientEnvSchema = z.object({
-  NEXT_PUBLIC_STRIPE_PUBLISHABLE_KEY: z.string().min(1),
-});
+export const StripeClientEnvSchema = z
+  .object({
+    publishableKey: z.string().min(1),
+  })
+  .refine(
+    (schema) => {
+      return schema.publishableKey.startsWith('pk_');
+    },
+    {
+      path: ['publishableKey'],
+      message: `Stripe publishable key must start with 'pk_'`,
+    },
+  );
diff --git a/packages/stripe/src/schema/stripe-server-env.schema.ts b/packages/stripe/src/schema/stripe-server-env.schema.ts
index c0bd7c5a7..d5e2d4d1f 100644
--- a/packages/stripe/src/schema/stripe-server-env.schema.ts
+++ b/packages/stripe/src/schema/stripe-server-env.schema.ts
@@ -1,6 +1,25 @@
 import { z } from 'zod';
 
-export const StripeServerEnvSchema = z.object({
-  STRIPE_SECRET_KEY: z.string().min(1),
-  STRIPE_WEBHOOK_SECRET: z.string().min(1),
-});
+export const StripeServerEnvSchema = z
+  .object({
+    secretKey: z.string().min(1),
+    webhooksSecret: z.string().min(1),
+  })
+  .refine(
+    (schema) => {
+      return schema.secretKey.startsWith('sk_');
+    },
+    {
+      path: ['STRIPE_SECRET_KEY'],
+      message: `Stripe secret key must start with 'sk_'`,
+    },
+  )
+  .refine(
+    (schema) => {
+      return schema.webhooksSecret.startsWith('whsec_');
+    },
+    {
+      path: ['STRIPE_WEBHOOK_SECRET'],
+      message: `Stripe webhook secret must start with 'whsec_'`,
+    },
+  );
diff --git a/packages/stripe/src/services/stripe-sdk.ts b/packages/stripe/src/services/stripe-sdk.ts
index ccff536a2..f0d9299cf 100644
--- a/packages/stripe/src/services/stripe-sdk.ts
+++ b/packages/stripe/src/services/stripe-sdk.ts
@@ -16,7 +16,7 @@ export async function createStripeClient() {
     STRIPE_WEBHOOK_SECRET: process.env.STRIPE_WEBHOOK_SECRET,
   });
 
-  return new Stripe(stripeServerEnv.STRIPE_SECRET_KEY, {
+  return new Stripe(stripeServerEnv.secretKey, {
     apiVersion: STRIPE_API_VERSION,
   });
 }
diff --git a/packages/stripe/src/services/stripe-webhook-handler.service.ts b/packages/stripe/src/services/stripe-webhook-handler.service.ts
index 19d867986..b0d55e8a4 100644
--- a/packages/stripe/src/services/stripe-webhook-handler.service.ts
+++ b/packages/stripe/src/services/stripe-webhook-handler.service.ts
@@ -32,9 +32,9 @@ export class StripeWebhookHandlerService
     const signatureKey = `stripe-signature`;
     const signature = request.headers.get(signatureKey)!;
 
-    const { STRIPE_WEBHOOK_SECRET } = StripeServerEnvSchema.parse({
-      STRIPE_SECRET_KEY: process.env.STRIPE_SECRET_KEY,
-      STRIPE_WEBHOOK_SECRET: process.env.STRIPE_WEBHOOK_SECRET,
+    const { webhooksSecret } = StripeServerEnvSchema.parse({
+      secretKey: process.env.STRIPE_SECRET_KEY,
+      webhooksSecret: process.env.STRIPE_WEBHOOK_SECRET,
     });
 
     const stripe = await this.loadStripe();
@@ -42,7 +42,7 @@ export class StripeWebhookHandlerService
     const event = stripe.webhooks.constructEvent(
       body,
       signature,
-      STRIPE_WEBHOOK_SECRET,
+      webhooksSecret,
     );
 
     if (!event) {