diff --git a/.changeset/cute-ideas-appear.md b/.changeset/cute-ideas-appear.md
new file mode 100644
index 00000000000..9b1d6379498
--- /dev/null
+++ b/.changeset/cute-ideas-appear.md
@@ -0,0 +1,6 @@
+---
+'@clerk/clerk-js': minor
+'@clerk/shared': minor
+---
+
+Add support for parsing seat-based billing fields from FAPI.
diff --git a/packages/clerk-js/src/core/resources/BillingPlan.ts b/packages/clerk-js/src/core/resources/BillingPlan.ts
index 6afbdbfe3b9..977e454cbd7 100644
--- a/packages/clerk-js/src/core/resources/BillingPlan.ts
+++ b/packages/clerk-js/src/core/resources/BillingPlan.ts
@@ -3,6 +3,7 @@ import type {
   BillingPayerResourceType,
   BillingPlanJSON,
   BillingPlanResource,
+  BillingPlanUnitPrice,
 } from '@clerk/shared/types';
 
 import { billingMoneyAmountFromJSON } from '@/utils/billing';
@@ -24,6 +25,7 @@ export class BillingPlan extends BaseResource implements BillingPlanResource {
   slug!: string;
   avatarUrl: string | null = null;
   features!: Feature[];
+  unitPrices?: BillingPlanUnitPrice[];
   freeTrialDays!: number | null;
   freeTrialEnabled!: boolean;
 
@@ -53,6 +55,16 @@ export class BillingPlan extends BaseResource implements BillingPlanResource {
     this.freeTrialDays = this.withDefault(data.free_trial_days, null);
     this.freeTrialEnabled = this.withDefault(data.free_trial_enabled, false);
     this.features = (data.features || []).map(feature => new Feature(feature));
+    this.unitPrices = data.unit_prices?.map(unitPrice => ({
+      name: unitPrice.name,
+      blockSize: unitPrice.block_size,
+      tiers: unitPrice.tiers.map(tier => ({
+        id: tier.id,
+        startsAtBlock: tier.starts_at_block,
+        endsAfterBlock: tier.ends_after_block,
+        feePerBlock: billingMoneyAmountFromJSON(tier.fee_per_block),
+      })),
+    }));
 
     return this;
   }
diff --git a/packages/clerk-js/src/core/resources/BillingSubscription.ts b/packages/clerk-js/src/core/resources/BillingSubscription.ts
index 3b80c7dbe66..f463c82646b 100644
--- a/packages/clerk-js/src/core/resources/BillingSubscription.ts
+++ b/packages/clerk-js/src/core/resources/BillingSubscription.ts
@@ -2,6 +2,7 @@ import type {
   BillingMoneyAmount,
   BillingSubscriptionItemJSON,
   BillingSubscriptionItemResource,
+  BillingSubscriptionItemSeats,
   BillingSubscriptionJSON,
   BillingSubscriptionPlanPeriod,
   BillingSubscriptionResource,
@@ -75,6 +76,7 @@ export class BillingSubscriptionItem extends BaseResource implements BillingSubs
   credit?: {
     amount: BillingMoneyAmount;
   };
+  seats?: BillingSubscriptionItemSeats;
   isFreeTrial!: boolean;
 
   constructor(data: BillingSubscriptionItemJSON) {
@@ -102,6 +104,7 @@ export class BillingSubscriptionItem extends BaseResource implements BillingSubs
     this.amount = data.amount ? billingMoneyAmountFromJSON(data.amount) : undefined;
     this.credit =
       data.credit && data.credit.amount ? { amount: billingMoneyAmountFromJSON(data.credit.amount) } : undefined;
+    this.seats = data.seats ? { quantity: data.seats.quantity } : undefined;
 
     this.isFreeTrial = this.withDefault(data.is_free_trial, false);
     return this;
diff --git a/packages/clerk-js/src/utils/billing.ts b/packages/clerk-js/src/utils/billing.ts
index a72868a859d..d795c2841f0 100644
--- a/packages/clerk-js/src/utils/billing.ts
+++ b/packages/clerk-js/src/utils/billing.ts
@@ -3,6 +3,8 @@ import type {
   BillingCheckoutTotalsJSON,
   BillingMoneyAmount,
   BillingMoneyAmountJSON,
+  BillingPerUnitTotal,
+  BillingPerUnitTotalJSON,
   BillingStatementTotals,
   BillingStatementTotalsJSON,
 } from '@clerk/shared/types';
@@ -16,6 +18,18 @@ export const billingMoneyAmountFromJSON = (data: BillingMoneyAmountJSON): Billin
   };
 };
 
+const billingPerUnitTotalsFromJSON = (data: BillingPerUnitTotalJSON[]): BillingPerUnitTotal[] => {
+  return data.map(unitTotal => ({
+    name: unitTotal.name,
+    blockSize: unitTotal.block_size,
+    tiers: unitTotal.tiers.map(tier => ({
+      quantity: tier.quantity,
+      feePerBlock: billingMoneyAmountFromJSON(tier.fee_per_block),
+      total: billingMoneyAmountFromJSON(tier.total),
+    })),
+  }));
+};
+
 export const billingTotalsFromJSON = <T extends BillingStatementTotalsJSON | BillingCheckoutTotalsJSON>(
   data: T,
 ): T extends { total_due_now: BillingMoneyAmountJSON } ? BillingCheckoutTotals : BillingStatementTotals => {
@@ -31,6 +45,9 @@ export const billingTotalsFromJSON = <T extends BillingStatementTotalsJSON | Bil
   if ('credit' in data) {
     totals.credit = data.credit ? billingMoneyAmountFromJSON(data.credit) : null;
   }
+  if ('per_unit_totals' in data) {
+    totals.perUnitTotals = data.per_unit_totals ? billingPerUnitTotalsFromJSON(data.per_unit_totals) : undefined;
+  }
 
   if ('total_due_now' in data) {
     totals.totalDueNow = billingMoneyAmountFromJSON(data.total_due_now);
diff --git a/packages/shared/src/types/billing.ts b/packages/shared/src/types/billing.ts
index fd6124f1337..16078e08e80 100644
--- a/packages/shared/src/types/billing.ts
+++ b/packages/shared/src/types/billing.ts
@@ -206,6 +206,10 @@ export interface BillingPlanResource extends ClerkResource {
    * The Features the Plan offers.
    */
   features: FeatureResource[];
+  /**
+   * Per-unit pricing tiers for this Plan (for example, seats).
+   */
+  unitPrices?: BillingPlanUnitPrice[];
   /**
    * The number of days of the free trial for the Plan. `null` if the Plan does not have a free trial.
    */
@@ -216,6 +220,102 @@ export interface BillingPlanResource extends ClerkResource {
   freeTrialEnabled: boolean;
 }
 
+/**
+ * The `BillingSubscriptionItemSeats` type represents seat entitlements attached to a subscription item.
+ *
+ * @experimental This is an experimental API for the Billing feature that is available under a public beta, and the API is subject to change. It is advised to [pin](https://clerk.com/docs/pinning) the SDK version and the clerk-js version to avoid breaking changes.
+ */
+export interface BillingSubscriptionItemSeats {
+  /**
+   * The seat limit active while the parent subscription item was active. `null` means unlimited.
+   */
+  quantity: number | null;
+}
+
+/**
+ * The `BillingPlanUnitPriceTier` type represents a single pricing tier for a unit type on a plan.
+ *
+ * @experimental This is an experimental API for the Billing feature that is available under a public beta, and the API is subject to change. It is advised to [pin](https://clerk.com/docs/pinning) the SDK version and the clerk-js version to avoid breaking changes.
+ */
+export interface BillingPlanUnitPriceTier {
+  /**
+   * The unique identifier of the unit price tier.
+   */
+  id: string;
+  /**
+   * The first block number this tier applies to.
+   */
+  startsAtBlock: number;
+  /**
+   * The final block this tier applies to. `null` means unlimited.
+   */
+  endsAfterBlock: number | null;
+  /**
+   * The fee charged for each block in this tier.
+   */
+  feePerBlock: BillingMoneyAmount;
+}
+
+/**
+ * The `BillingPlanUnitPrice` type represents unit pricing for a specific unit type (for example, seats) on a plan.
+ *
+ * @experimental This is an experimental API for the Billing feature that is available under a public beta, and the API is subject to change. It is advised to [pin](https://clerk.com/docs/pinning) the SDK version and the clerk-js version to avoid breaking changes.
+ */
+export interface BillingPlanUnitPrice {
+  /**
+   * The unit name, for example `seats`.
+   */
+  name: string;
+  /**
+   * Number of units represented by one billable block.
+   */
+  blockSize: number;
+  /**
+   * Tiers that define how each block range is priced.
+   */
+  tiers: BillingPlanUnitPriceTier[];
+}
+
+/**
+ * The `BillingPerUnitTotalTier` type represents the cost breakdown for a single tier in checkout totals.
+ *
+ * @experimental This is an experimental API for the Billing feature that is available under a public beta, and the API is subject to change. It is advised to [pin](https://clerk.com/docs/pinning) the SDK version and the clerk-js version to avoid breaking changes.
+ */
+export interface BillingPerUnitTotalTier {
+  /**
+   * The quantity billed within this tier. `null` means unlimited.
+   */
+  quantity: number | null;
+  /**
+   * The fee charged per block for this tier.
+   */
+  feePerBlock: BillingMoneyAmount;
+  /**
+   * The total billed amount for this tier.
+   */
+  total: BillingMoneyAmount;
+}
+
+/**
+ * The `BillingPerUnitTotal` type represents the per-unit cost breakdown in checkout totals.
+ *
+ * @experimental This is an experimental API for the Billing feature that is available under a public beta, and the API is subject to change. It is advised to [pin](https://clerk.com/docs/pinning) the SDK version and the clerk-js version to avoid breaking changes.
+ */
+export interface BillingPerUnitTotal {
+  /**
+   * The unit name, for example `seats`.
+   */
+  name: string;
+  /**
+   * Number of units represented by one billable block.
+   */
+  blockSize: number;
+  /**
+   * Detailed tier breakdown for this unit total.
+   */
+  tiers: BillingPerUnitTotalTier[];
+}
+
 /**
  * The `FeatureResource` type represents a Feature of a Plan.
  *
@@ -593,6 +693,11 @@ export interface BillingSubscriptionItemResource extends ClerkResource {
      */
     amount: BillingMoneyAmount;
   };
+  /**
+   * Seat entitlement details for this subscription item. Only set for organization subscription items with
+   * seat-based billing.
+   */
+  seats?: BillingSubscriptionItemSeats;
   /**
    * A function to cancel the subscription item. Accepts the following parameters:
    * <ul>
@@ -708,6 +813,10 @@ export interface BillingCheckoutTotals {
    * The amount of tax included in the checkout.
    */
   taxTotal: BillingMoneyAmount;
+  /**
+   * Per-unit cost breakdown for this checkout (for example, seats).
+   */
+  perUnitTotals?: BillingPerUnitTotal[];
   /**
    * The amount that needs to be immediately paid to complete the checkout.
    */
diff --git a/packages/shared/src/types/json.ts b/packages/shared/src/types/json.ts
index 5ce69d083d4..c56fd4ce9c4 100644
--- a/packages/shared/src/types/json.ts
+++ b/packages/shared/src/types/json.ts
@@ -596,6 +596,68 @@ export interface FeatureJSON extends ClerkResourceJSON {
   avatar_url: string | null;
 }
 
+/**
+ * @experimental This is an experimental API for the Billing feature that is available under a public beta, and the API is subject to change. It is advised to [pin](https://clerk.com/docs/pinning) the SDK version and the clerk-js version to avoid breaking changes.
+ */
+export interface BillingSubscriptionItemSeatsJSON {
+  /**
+   * The number of seats available. `null` means unlimited.
+   */
+  quantity: number | null;
+}
+
+/**
+ * @experimental This is an experimental API for the Billing feature that is available under a public beta, and the API is subject to change. It is advised to [pin](https://clerk.com/docs/pinning) the SDK version and the clerk-js version to avoid breaking changes.
+ *
+ * Represents a single pricing tier for a unit type on a plan.
+ */
+export interface BillingPlanUnitPriceTierJSON {
+  id: string;
+  object: 'commerce_unit_price';
+  starts_at_block: number;
+  /**
+   * `null` means unlimited.
+   */
+  ends_after_block: number | null;
+  fee_per_block: BillingMoneyAmountJSON;
+}
+
+/**
+ * @experimental This is an experimental API for the Billing feature that is available under a public beta, and the API is subject to change. It is advised to [pin](https://clerk.com/docs/pinning) the SDK version and the clerk-js version to avoid breaking changes.
+ *
+ * Represents unit pricing for a specific unit type (for example, seats) on a plan.
+ */
+export interface BillingPlanUnitPriceJSON {
+  name: string;
+  block_size: number;
+  tiers: BillingPlanUnitPriceTierJSON[];
+}
+
+/**
+ * @experimental This is an experimental API for the Billing feature that is available under a public beta, and the API is subject to change. It is advised to [pin](https://clerk.com/docs/pinning) the SDK version and the clerk-js version to avoid breaking changes.
+ *
+ * Represents the cost breakdown for a single tier in checkout totals.
+ */
+export interface BillingPerUnitTotalTierJSON {
+  /**
+   * `null` means unlimited.
+   */
+  quantity: number | null;
+  fee_per_block: BillingMoneyAmountJSON;
+  total: BillingMoneyAmountJSON;
+}
+
+/**
+ * @experimental This is an experimental API for the Billing feature that is available under a public beta, and the API is subject to change. It is advised to [pin](https://clerk.com/docs/pinning) the SDK version and the clerk-js version to avoid breaking changes.
+ *
+ * Represents the per-unit cost breakdown in checkout totals.
+ */
+export interface BillingPerUnitTotalJSON {
+  name: string;
+  block_size: number;
+  tiers: BillingPerUnitTotalTierJSON[];
+}
+
 /**
  * @experimental This is an experimental API for the Billing feature that is available under a public beta, and the API is subject to change. It is advised to [pin](https://clerk.com/docs/pinning) the SDK version and the clerk-js version to avoid breaking changes.
  */
@@ -617,6 +679,10 @@ export interface BillingPlanJSON extends ClerkResourceJSON {
   features?: FeatureJSON[];
   free_trial_days?: number | null;
   free_trial_enabled?: boolean;
+  /**
+   * Per-unit pricing tiers for this plan (for example, seats).
+   */
+  unit_prices?: BillingPlanUnitPriceJSON[];
 }
 
 /**
@@ -695,6 +761,11 @@ export interface BillingSubscriptionItemJSON extends ClerkResourceJSON {
   credit?: {
     amount: BillingMoneyAmountJSON;
   };
+  /**
+   * Seat entitlement details for this subscription item. Only set for organization subscription items with
+   * seat-based billing.
+   */
+  seats?: BillingSubscriptionItemSeatsJSON;
   plan: BillingPlanJSON;
   plan_period: BillingSubscriptionPlanPeriod;
   status: BillingSubscriptionStatus;
@@ -751,6 +822,10 @@ export interface BillingCheckoutTotalsJSON {
   grand_total: BillingMoneyAmountJSON;
   subtotal: BillingMoneyAmountJSON;
   tax_total: BillingMoneyAmountJSON;
+  /**
+   * Per-unit cost breakdown for this checkout (for example, seats).
+   */
+  per_unit_totals?: BillingPerUnitTotalJSON[];
   total_due_now: BillingMoneyAmountJSON;
   credit: BillingMoneyAmountJSON | null;
   past_due: BillingMoneyAmountJSON | null;