diff --git a/packages/localizations/src/en-US.ts b/packages/localizations/src/en-US.ts
index be7dcff8482..7d91a056ccc 100644
--- a/packages/localizations/src/en-US.ts
+++ b/packages/localizations/src/en-US.ts
@@ -535,6 +535,7 @@ export const enUS: LocalizationResource = {
       detailsTitle__inviteFailed:
         'The invitations could not be sent. There are already pending invitations for the following email addresses: {{email_addresses}}.',
       formButtonPrimary__continue: 'Send invitations',
+      formButtonPrimary__purchaseSeats: 'Purchase additional seats',
       selectDropdown__role: 'Select role',
       subtitle: 'Enter or paste one or more email addresses, separated by spaces or commas.',
       successMessage: 'Invitations successfully sent',
diff --git a/packages/shared/src/types/localization.ts b/packages/shared/src/types/localization.ts
index 3bb00ce6831..c53b1ecd020 100644
--- a/packages/shared/src/types/localization.ts
+++ b/packages/shared/src/types/localization.ts
@@ -1110,6 +1110,7 @@ export type __internal_LocalizationResource = {
       successMessage: LocalizationValue;
       detailsTitle__inviteFailed: LocalizationValue<'email_addresses'>;
       formButtonPrimary__continue: LocalizationValue;
+      formButtonPrimary__purchaseSeats: LocalizationValue;
       selectDropdown__role: LocalizationValue;
     };
     removeDomainPage: {
diff --git a/packages/ui/src/components/OrganizationProfile/InviteMembersForm.tsx b/packages/ui/src/components/OrganizationProfile/InviteMembersForm.tsx
index 3a8ecc68b8d..38767d1691b 100644
--- a/packages/ui/src/components/OrganizationProfile/InviteMembersForm.tsx
+++ b/packages/ui/src/components/OrganizationProfile/InviteMembersForm.tsx
@@ -8,11 +8,16 @@ import { useCardState } from '@/ui/elements/contexts';
 import { Form } from '@/ui/elements/Form';
 import { FormButtonContainer } from '@/ui/elements/FormButtons';
 import { TagInput } from '@/ui/elements/TagInput';
+import {
+  getPaidSeatsUnitTier,
+  getSeatUnitPrice,
+  organizationAndInvitationsExceedsPurchasedSeats,
+} from '@/ui/utils/billingPlanSeats';
 import { handleError } from '@/ui/utils/errorHandler';
 import { createListFormat } from '@/ui/utils/passwordUtils';
 import { useFormControl } from '@/ui/utils/useFormControl';
 
-import { useEnvironment } from '../../contexts';
+import { useEnvironment, useSubscription } from '../../contexts';
 import { Flex } from '../../customizables';
 import { useFetchRoles } from '../../hooks/useFetchRoles';
 import type { LocalizationKey } from '../../localization';
@@ -37,6 +42,8 @@ export const InviteMembersForm = (props: InviteMembersFormProps) => {
       keepPreviousData: true,
     },
   });
+  const { data: subscription } = useSubscription();
+  const activeSubscriptionItem = subscription?.subscriptionItems.find(si => si.status === 'active');
   const card = useCardState();
   const { t, locale } = useLocalizations();
   const [isValidUnsubmittedEmail, setIsValidUnsubmittedEmail] = useState(false);
@@ -74,6 +81,14 @@ export const InviteMembersForm = (props: InviteMembersFormProps) => {
   } = emailAddressField;
 
   const canSubmit = (!!emailAddressField.value.length || isValidUnsubmittedEmail) && !!roleField.value;
+  const emailAddresses = emailAddressField.value.split(',');
+
+  const seatUnitPrice = activeSubscriptionItem ? getSeatUnitPrice(activeSubscriptionItem.plan) : null;
+  const paidSeatsTier = seatUnitPrice ? getPaidSeatsUnitTier(seatUnitPrice) : null;
+  const isPerSeatCostPlan = !!paidSeatsTier;
+  const mustPurchaseSeats =
+    isPerSeatCostPlan &&
+    organizationAndInvitationsExceedsPurchasedSeats(activeSubscriptionItem, organization, emailAddresses.length);
 
   const onSubmit = (e: FormEvent<HTMLFormElement>) => {
     e.preventDefault();
@@ -84,7 +99,7 @@ export const InviteMembersForm = (props: InviteMembersFormProps) => {
     const submittedData = new FormData(e.currentTarget);
     return organization
       .inviteMembers({
-        emailAddresses: emailAddressField.value.split(','),
+        emailAddresses,
         role: submittedData.get('role') as string,
       })
       .then(async () => {
@@ -176,7 +191,11 @@ export const InviteMembersForm = (props: InviteMembersFormProps) => {
           <Form.SubmitButton
             block={false}
             isDisabled={!canSubmit}
-            localizationKey={localizationKeys('organizationProfile.invitePage.formButtonPrimary__continue')}
+            localizationKey={
+              isPerSeatCostPlan && mustPurchaseSeats
+                ? localizationKeys('organizationProfile.invitePage.formButtonPrimary__purchaseSeats')
+                : localizationKeys('organizationProfile.invitePage.formButtonPrimary__continue')
+            }
           />
           <Form.ResetButton
             localizationKey={resetButtonLabel || localizationKeys('userProfile.formButtonReset')}
diff --git a/packages/ui/src/utils/billingPlanSeats.ts b/packages/ui/src/utils/billingPlanSeats.ts
index c7805ee8f2b..e03b1c24010 100644
--- a/packages/ui/src/utils/billingPlanSeats.ts
+++ b/packages/ui/src/utils/billingPlanSeats.ts
@@ -3,6 +3,8 @@ import type {
   BillingPerUnitTotalTier,
   BillingPlanResource,
   BillingPlanUnitPrice,
+  BillingPlanUnitPriceTier,
+  BillingSubscriptionItemResource,
   OrganizationResource,
 } from '@clerk/shared/types';
 
@@ -86,6 +88,26 @@ export const getIncludedSeatsUnitTotalTier = (
   return null;
 };
 
+export const getPaidSeatsUnitTier = (unitPrice: BillingPlanUnitPrice | null): BillingPlanUnitPriceTier | null => {
+  if (!unitPrice) {
+    return null;
+  }
+
+  if (unitPrice.tiers.length === 1 && unitPrice.tiers[0].feePerBlock.amount > 0) {
+    return unitPrice.tiers[0];
+  }
+
+  if (
+    unitPrice.tiers.length === 2 &&
+    unitPrice.tiers[0].feePerBlock.amount === 0 &&
+    unitPrice.tiers[1].feePerBlock.amount > 0
+  ) {
+    return unitPrice.tiers[1];
+  }
+
+  return null;
+};
+
 /**
  * Given a plan, return the seat limit for the plan, or undefined if the plan does not have a seat limit.
  */
@@ -114,3 +136,18 @@ export const organizationExceedsPlanSeatLimit = (
 
   return organization.membersCount + organization.pendingInvitationsCount > seatLimit;
 };
+
+export const organizationAndInvitationsExceedsPurchasedSeats = (
+  subscriptionItem: BillingSubscriptionItemResource | undefined,
+  organization: OrganizationResource,
+  invitationsCount: number,
+): boolean => {
+  if (!subscriptionItem || !subscriptionItem.seats || !subscriptionItem.seats.quantity) {
+    return false;
+  }
+
+  return (
+    organization.membersCount + organization.pendingInvitationsCount + invitationsCount >
+    subscriptionItem.seats.quantity
+  );
+};