diff --git a/lib/connect-account-links.ts b/lib/connect-account-links.ts
index 0d909a8..d03a77e 100644
--- a/lib/connect-account-links.ts
+++ b/lib/connect-account-links.ts
@@ -62,3 +62,28 @@ export function onboardingLinkForm(accountId: string, pageUrl: string): Record<s
     return_url: pageUrl,
   };
 }
+
+/**
+ * The tenant's own onboarding page — the URL that goes into the registry entry
+ * (`payments_link_url:`) and from there into the tenant's `Stripe:PaymentsLinkUrl`
+ * setting, which is what the restaurant's Payments tab links to.
+ *
+ * NO LOCALE PREFIX, deliberately. `middleware.ts` redirects an unprefixed path to
+ * the visitor's own language, so one stored URL serves a Swiss restaurant whose
+ * staff read French and whose owner reads German. Baking `/en/` in would pick for
+ * them, permanently, in a value that is copied into a box `.env`.
+ *
+ * The BASE is passed in rather than read here so this stays pure and so the
+ * caller uses the one seam every link we send already goes through
+ * (`siteUrl()` — runtime `NEXTAUTH_URL` first, so staging cannot mint links that
+ * point at production).
+ */
+export function paymentsPageUrl(baseUrl: string, token: string): string {
+  // Built with the URL constructor rather than by trimming a trailing slash off
+  // the base: `NEXTAUTH_URL` is hand-written in a box `.env`, and the obvious
+  // `replace(/\/+$/, "")` is the ReDoS shape Sonar rejects (S5852) — the same
+  // reason lib/provisioning.ts uses `trimEnd()` instead of `\n*$`. This also
+  // normalises the join, so `https://host/` and `https://host` cannot produce two
+  // different links.
+  return new URL(`/onboarding/payments/${token}`, baseUrl).toString();
+}
diff --git a/lib/provisioning-mint.ts b/lib/provisioning-mint.ts
index f7cd7fc..3546e02 100644
--- a/lib/provisioning-mint.ts
+++ b/lib/provisioning-mint.ts
@@ -27,6 +27,8 @@
 //     payments is a real object with a real compliance obligation attached.
 
 import { createExpressAccount } from "@/lib/stripe-connect-accounts";
+import { paymentsPageUrl } from "@/lib/connect-account-links";
+import { siteUrl } from "@/lib/email";
 import { connectCountryForCurrency } from "@/lib/connect-account-country";
 import { isStripeAccountId } from "@/lib/validation-provision";
 import { stripeConfigured } from "@/lib/stripe";
@@ -45,6 +47,16 @@ export type MintForProposalInput = {
 export type MintForProposalResult = {
   /** The minted (or already-recorded) `acct_…`, when there is one. */
   stripeAccount?: string;
+  /**
+   * The tenant's own `/onboarding/payments/<token>` URL, finished and absolute —
+   * never a raw token. It travels into the registry entry as `payments_link_url:`
+   * and from there into the tenant's `Stripe:PaymentsLinkUrl`, so the deploy repo
+   * copies one opaque field and never learns that a token is a token. It also
+   * cannot get the origin subtly wrong per environment, which is the failure a
+   * box-side concatenation would eventually produce: a link that works and points
+   * at the wrong site.
+   */
+  paymentsLinkUrl?: string;
   /**
    * Why there is none — founder-facing, and written into the PR body. Absent when
    * nothing was attempted (the tenant did not buy the module) or when it worked.
@@ -84,7 +96,13 @@ export async function mintForProposal(input: MintForProposalInput): Promise<Mint
     if (!isStripeAccountId(minted.stripeAccountId)) {
       return { note: `Stripe returned an account id in an unexpected shape and it was not recorded in the entry` };
     }
-    return { stripeAccount: minted.stripeAccountId };
+    return {
+      stripeAccount: minted.stripeAccountId,
+      // `siteUrl()` — the ONE base every link we send already goes through
+      // (runtime NEXTAUTH_URL first), so staging can never mint a link that
+      // points at production.
+      paymentsLinkUrl: paymentsPageUrl(siteUrl(), minted.onboardingToken),
+    };
   } catch (e) {
     // No PII: a slug and Stripe's own message (CLAUDE.md §5.8).
     console.error("mintForProposal failed", input.slug, e);
diff --git a/lib/provisioning-registry.ts b/lib/provisioning-registry.ts
index ba29d7c..0336692 100644
--- a/lib/provisioning-registry.ts
+++ b/lib/provisioning-registry.ts
@@ -48,6 +48,15 @@ export interface TenantProvisionInput {
    * Absent only when the mint could not happen, which `stripeAccountNote` explains.
    */
   stripeAccount?: string;
+  /**
+   * The tenant's own onboarding page (`https://…/onboarding/payments/<token>`),
+   * server-derived exactly like `stripeAccount` and emitted BESIDE it. It becomes
+   * the tenant's `Stripe:PaymentsLinkUrl`, i.e. the button in their own Payments
+   * tab. One opaque field: `provision-tenant.sh` copies it and never learns that
+   * part of it is a credential, and no per-environment concatenation can put a
+   * working link in front of the wrong site.
+   */
+  paymentsLinkUrl?: string;
   /**
    * Why there is no `stripeAccount`, in founder-facing words. NOT a registry field —
    * `buildTenantRegistryEntry` ignores it entirely; it exists so the PR body can say
@@ -155,6 +164,11 @@ export function buildTenantRegistryEntry(input: TenantProvisionInput): {
       // it — the two are written from the same `granted`/`stripeAccount` pair so the
       // entry can never carry one half of the guard's condition.
       ...(stripeAccount ? { stripe_account: stripeAccount } : {}),
+      // Emitted only ALONGSIDE the account, never on its own: without an account
+      // there is no onboarding page to point at, and a link to a page that 404s is
+      // worse than no button at all. Same pairing discipline as the two fields
+      // above, one field along.
+      ...(stripeAccount && input.paymentsLinkUrl ? { payments_link_url: input.paymentsLinkUrl } : {}),
       // Whether the rate belongs in THIS entry: grantedCommissionBps (same pairing
       // rule as stripe_account above, applied to a second field).
       ...(commissionBps !== undefined ? { payments_commission_bps: commissionBps } : {}),
diff --git a/lib/provisioning.ts b/lib/provisioning.ts
index b2681c0..6de0486 100644
--- a/lib/provisioning.ts
+++ b/lib/provisioning.ts
@@ -123,6 +123,7 @@ export async function openProvisioningPr(
     ...input,
     partnerBrand,
     ...(mint.stripeAccount ? { stripeAccount: mint.stripeAccount } : {}),
+    ...(mint.paymentsLinkUrl ? { paymentsLinkUrl: mint.paymentsLinkUrl } : {}),
     ...(mint.note ? { stripeAccountNote: mint.note } : {}),
   };
 
diff --git a/lib/stripe-connect-accounts.ts b/lib/stripe-connect-accounts.ts
index 6576e04..2bdcf24 100644
--- a/lib/stripe-connect-accounts.ts
+++ b/lib/stripe-connect-accounts.ts
@@ -43,6 +43,12 @@ type StripeAccountCreated = { id: string };
 export type MintedConnectAccount = {
   /** `acct_...` */
   stripeAccountId: string;
+  /**
+   * The unguessable segment of this tenant's `/onboarding/payments/<token>` page
+   * (E4). Returned so the caller can put the finished URL in the registry entry
+   * — the box never sees the token as a token, only a URL it copies.
+   */
+  onboardingToken: string;
   /**
    * True when the account already existed for this slug and no Stripe call was
    * made. Reported rather than hidden because the caller's audit line should say
@@ -57,9 +63,16 @@ export async function createExpressAccount(input: ExpressAccountInput): Promise<
   const form = expressAccountForm(input);
 
   const existing = await findConnectAccountForSlug(input.slug);
-  if (existing) return { stripeAccountId: existing.stripeAccountId, reused: true };
+  if (existing) {
+    return {
+      stripeAccountId: existing.stripeAccountId,
+      onboardingToken: existing.onboardingToken,
+      reused: true,
+    };
+  }
 
   const account = await stripePost<StripeAccountCreated>("/v1/accounts", form, { idempotencyKey });
+  const onboardingToken = newOnboardingToken();
 
   // Not in a transaction with the call above, because there is no such thing: the
   // account exists at Stripe the moment it returns. What makes the gap survivable
@@ -72,10 +85,10 @@ export async function createExpressAccount(input: ExpressAccountInput): Promise<
     country: form.country,
     // Minted here, with the account, and never re-issued: it is how the restaurant
     // reaches its own onboarding page for as long as that page exists.
-    onboardingToken: newOnboardingToken(),
+    onboardingToken,
   });
 
-  return { stripeAccountId: account.id, reused: false };
+  return { stripeAccountId: account.id, onboardingToken, reused: false };
 }
 
 /** Stripe's `AccountLink` / `LoginLink` — both are `{ url }` and nothing else is read. */
diff --git a/tests/unit/connect-account-links.test.ts b/tests/unit/connect-account-links.test.ts
index a6417b4..595b8de 100644
--- a/tests/unit/connect-account-links.test.ts
+++ b/tests/unit/connect-account-links.test.ts
@@ -1,5 +1,5 @@
 import { describe, expect, it } from "vitest";
-import { chooseConnectLink, onboardingLinkForm } from "@/lib/connect-account-links";
+import { chooseConnectLink, onboardingLinkForm, paymentsPageUrl } from "@/lib/connect-account-links";
 import { newOnboardingToken } from "@/lib/connect-account-store";
 import { resolvePaymentsLink } from "@/lib/onboarding-payments";
 
@@ -81,3 +81,34 @@ describe("resolvePaymentsLink", () => {
     });
   });
 });
+
+describe("paymentsPageUrl — what goes into the registry entry", () => {
+  it("is the page's own URL with NO locale prefix", () => {
+    // `middleware.ts` redirects an unprefixed path to the visitor's language, so
+    // one stored URL serves a Swiss restaurant whose staff read French and whose
+    // owner reads German. Baking `/en/` in would choose for them, permanently, in
+    // a value that is copied into a box `.env`.
+    expect(paymentsPageUrl("https://sofrapiwas.com", "tok123")).toBe(
+      "https://sofrapiwas.com/onboarding/payments/tok123",
+    );
+    expect(paymentsPageUrl("https://sofrapiwas.com", "tok123")).not.toContain("/en/");
+  });
+
+  it("survives a base URL with a trailing slash", () => {
+    // `NEXTAUTH_URL` is hand-written in a box `.env`; a trailing slash there would
+    // otherwise produce `//onboarding/...`, which is a different path and a 404 on
+    // the day somebody is trying to get paid.
+    expect(paymentsPageUrl("https://staging.sofrapiwas.com/", "tok")).toBe(
+      "https://staging.sofrapiwas.com/onboarding/payments/tok",
+    );
+    expect(paymentsPageUrl("https://staging.sofrapiwas.com///", "tok")).toBe(
+      "https://staging.sofrapiwas.com/onboarding/payments/tok",
+    );
+  });
+
+  it("keeps the environment it was given", () => {
+    // The reason the URL is finished HERE and not on the box: a per-environment
+    // concatenation eventually points a working link at the wrong site.
+    expect(paymentsPageUrl("https://staging.sofrapiwas.com", "t")).toContain("staging.");
+  });
+});
diff --git a/tests/unit/provisioning-registry.test.ts b/tests/unit/provisioning-registry.test.ts
index 35d6ded..98ee448 100644
--- a/tests/unit/provisioning-registry.test.ts
+++ b/tests/unit/provisioning-registry.test.ts
@@ -319,6 +319,35 @@ describe("deferring online-payments out of the generated entry", () => {
     expect(deferred).toEqual(["online-payments"]);
   });
 
+  it("emits payments_link_url beside the account, and never without one", () => {
+    // The tenant's own onboarding page, finished here and copied verbatim by
+    // provision-tenant.sh into `Stripe:PaymentsLinkUrl`. It is PAIRED with the
+    // account for the same reason the module is: with no account there is no
+    // onboarding page to point at, and a button that 404s is worse than no button.
+    const withAccount = buildTenantRegistryEntry({
+      ...base,
+      modules: bought,
+      stripeAccount: "acct_1UCOkhCSPiP2JWOQ",
+      paymentsLinkUrl: "https://sofrapiwas.com/onboarding/payments/tok123",
+    });
+    const t = asTenant(withAccount, base.slug) as Record<string, unknown>;
+    expect(t.payments_link_url).toBe("https://sofrapiwas.com/onboarding/payments/tok123");
+    expect(t.stripe_account).toBe("acct_1UCOkhCSPiP2JWOQ");
+
+    // No account: the link is withheld even though it was supplied.
+    const orphan = buildTenantRegistryEntry({
+      ...base,
+      modules: bought,
+      paymentsLinkUrl: "https://sofrapiwas.com/onboarding/payments/tok123",
+    });
+    expect("payments_link_url" in (asTenant(orphan, base.slug) as Record<string, unknown>)).toBe(false);
+
+    // And an entry that never asked for one is byte-identical to what this
+    // generator emitted before the field existed.
+    const none = buildTenantRegistryEntry({ ...base, modules: bought });
+    expect("payments_link_url" in (asTenant(none, base.slug) as Record<string, unknown>)).toBe(false);
+  });
+
   it("changes nothing for a tenant that did not buy it", () => {
     // The strip must be surgical: a generator that quietly dropped ids would be the same
     // class of bug pointed the other way.