diff --git a/packages/auth/src/lib/accept-invitation-endpoint.ts b/packages/auth/src/lib/accept-invitation-endpoint.ts
index cf92258f113..d9b0f95e135 100644
--- a/packages/auth/src/lib/accept-invitation-endpoint.ts
+++ b/packages/auth/src/lib/accept-invitation-endpoint.ts
@@ -133,10 +133,18 @@ export const acceptInvitationEndpoint = {
 				});
 
 				if (!existingMember) {
-					await db.insert(members).values({
-						organizationId: invitation.organization.id,
-						userId: user.id,
-						role: invitation.role ?? "member",
+					// Dynamic import: this plugin needs to call the organization plugin's
+					// addMember API to trigger billing hooks (beforeAddMember/afterAddMember).
+					// server.ts imports this file as a plugin, so a static import would be circular.
+					// The import resolves at request time when all modules are fully initialized.
+					const { auth } = await import("../server");
+					await auth.api.addMember({
+						body: {
+							organizationId: invitation.organization.id,
+							userId: user.id,
+							role:
+								(invitation.role as "member" | "owner" | "admin") ?? "member",
+						},
 					});
 				}
 
diff --git a/packages/trpc/src/router/organization/organization.ts b/packages/trpc/src/router/organization/organization.ts
index 2409981e16b..baf4b1f19ea 100644
--- a/packages/trpc/src/router/organization/organization.ts
+++ b/packages/trpc/src/router/organization/organization.ts
@@ -320,15 +320,15 @@ export const organizationRouter = {
 				userId: z.string().uuid(),
 			}),
 		)
-		.mutation(async ({ input }) => {
-			const [member] = await db
-				.insert(members)
-				.values({
+		.mutation(async ({ ctx, input }) => {
+			const member = await ctx.auth.api.addMember({
+				body: {
 					organizationId: input.organizationId,
 					userId: input.userId,
 					role: "member",
-				})
-				.returning();
+				},
+				headers: ctx.headers,
+			});
 			return member;
 		}),