diff --git a/backend/services/stellar/__tests__/qrPaymentService.test.ts b/backend/services/stellar/__tests__/qrPaymentService.test.ts
new file mode 100644
index 00000000..ab77e22d
--- /dev/null
+++ b/backend/services/stellar/__tests__/qrPaymentService.test.ts
@@ -0,0 +1,429 @@
+/**
+ * Tests for QRPaymentService and helpers (Issue #1714).
+ *
+ * Unit tests simulate the QR encoding path without any real Stellar network
+ * calls or external QR libraries.
+ */
+
+import {
+  QRPaymentService,
+  InMemoryQRPaymentStore,
+  buildSep007Uri,
+  buildQrDataUri,
+  STELLAR_NETWORK_PASSPHRASES,
+  type QRPaymentRequest,
+  type Clock,
+  type IdGenerator,
+} from '../qrPaymentService';
+
+// ── Test helpers ──────────────────────────────────────────────────────────────
+
+/** Deterministic clock that always returns the same timestamp. */
+class FixedClock implements Clock {
+  constructor(private readonly ts: number = 1_700_000_000_000) {}
+  now(): number {
+    return this.ts;
+  }
+}
+
+/** Deterministic ID generator that returns sequential IDs. */
+class SequentialIdGenerator implements IdGenerator {
+  private counter = 0;
+  generate(): string {
+    return `qr_test_${++this.counter}`;
+  }
+}
+
+function makeService(clockTs?: number): {
+  service: QRPaymentService;
+  store: InMemoryQRPaymentStore;
+  clock: FixedClock;
+  idGen: SequentialIdGenerator;
+} {
+  const store = new InMemoryQRPaymentStore();
+  const clock = new FixedClock(clockTs);
+  const idGen = new SequentialIdGenerator();
+  const service = new QRPaymentService(store, clock, idGen);
+  return { service, store, clock, idGen };
+}
+
+const VALID_ADDRESS = 'GBVHA6BLNPGMWNMWQMNCQUQNKGWZWL4RPXKC4MZQDOOFICMCF5I6HET';
+const VALID_ISSUER = 'GCEZWKCA5VLDNRLN3RPRJMRZOX3Z6G5CHCGZ4ONFAKK41VPK43CTJEW';
+
+function makeBaseRequest(overrides: Partial<QRPaymentRequest> = {}): QRPaymentRequest {
+  return {
+    id: 'qr_base_1',
+    merchantId: 'merchant_abc',
+    destinationAddress: VALID_ADDRESS,
+    amount: '10.50',
+    asset: 'XLM',
+    network: 'testnet',
+    createdAt: 1_700_000_000_000,
+    ...overrides,
+  };
+}
+
+// ── buildSep007Uri ────────────────────────────────────────────────────────────
+
+describe('buildSep007Uri', () => {
+  it('builds correct SEP-0007 URI for XLM (native asset)', () => {
+    const request = makeBaseRequest({ asset: 'XLM' });
+    const uri = buildSep007Uri(request);
+
+    expect(uri).toMatch(/^web\+stellar:pay\?/);
+    expect(uri).toContain(`destination=${encodeURIComponent(VALID_ADDRESS)}`);
+    expect(uri).toContain('amount=10.50');
+    // native XLM: no asset_code or asset_issuer
+    expect(uri).not.toContain('asset_code');
+    expect(uri).not.toContain('asset_issuer');
+  });
+
+  it('builds correct SEP-0007 URI for non-native asset (USDC) with issuer', () => {
+    const request = makeBaseRequest({
+      asset: 'USDC',
+      issuer: VALID_ISSUER,
+    });
+    const uri = buildSep007Uri(request);
+
+    expect(uri).toContain(`asset_code=USDC`);
+    expect(uri).toContain(`asset_issuer=${encodeURIComponent(VALID_ISSUER)}`);
+    expect(uri).toContain(`destination=${encodeURIComponent(VALID_ADDRESS)}`);
+  });
+
+  it('includes correct network_passphrase for testnet', () => {
+    const request = makeBaseRequest({ network: 'testnet' });
+    const uri = buildSep007Uri(request);
+
+    expect(uri).toContain(
+      `network_passphrase=${encodeURIComponent(STELLAR_NETWORK_PASSPHRASES.testnet)}`,
+    );
+  });
+
+  it('includes correct network_passphrase for mainnet', () => {
+    const request = makeBaseRequest({ network: 'mainnet' });
+    const uri = buildSep007Uri(request);
+
+    expect(uri).toContain(
+      `network_passphrase=${encodeURIComponent(STELLAR_NETWORK_PASSPHRASES.mainnet)}`,
+    );
+  });
+
+  it('URL-encodes memo with spaces and special chars', () => {
+    const memo = 'order 42 / test&check';
+    const request = makeBaseRequest({ memo });
+    const uri = buildSep007Uri(request);
+
+    expect(uri).toContain(`memo=${encodeURIComponent(memo)}`);
+    // raw spaces or & must not appear unencoded
+    expect(uri).not.toMatch(/memo=order 42/);
+  });
+
+  it('omits memo from URI when memo is not provided', () => {
+    const request = makeBaseRequest({ memo: undefined });
+    const uri = buildSep007Uri(request);
+
+    expect(uri).not.toContain('memo=');
+  });
+
+  it('omits asset_issuer when non-native asset has no issuer', () => {
+    const request = makeBaseRequest({ asset: 'USDT', issuer: undefined });
+    const uri = buildSep007Uri(request);
+
+    expect(uri).toContain('asset_code=USDT');
+    expect(uri).not.toContain('asset_issuer');
+  });
+
+  it('treats XLM case-insensitively as native (xlm lowercase)', () => {
+    const request = makeBaseRequest({ asset: 'xlm' });
+    const uri = buildSep007Uri(request);
+
+    expect(uri).not.toContain('asset_code');
+  });
+});
+
+// ── buildQrDataUri ────────────────────────────────────────────────────────────
+
+describe('buildQrDataUri', () => {
+  it('produces a valid base64 data URI', () => {
+    const sep007Uri = 'web+stellar:pay?destination=GABCDE&amount=5';
+    const dataUri = buildQrDataUri(sep007Uri);
+
+    expect(dataUri).toMatch(/^data:text\/plain;base64,/);
+    // base64 chars only after the prefix
+    const b64 = dataUri.replace('data:text/plain;base64,', '');
+    expect(b64).toMatch(/^[A-Za-z0-9+/]+=*$/);
+  });
+
+  it('decodes the base64 payload back to the original SEP-0007 URI', () => {
+    const sep007Uri =
+      'web+stellar:pay?destination=GABCDE&amount=10&network_passphrase=Test+SDF+Network+%3B+September+2015';
+    const dataUri = buildQrDataUri(sep007Uri);
+    const b64 = dataUri.replace('data:text/plain;base64,', '');
+    const decoded = Buffer.from(b64, 'base64').toString('utf8');
+
+    expect(decoded).toBe(sep007Uri);
+  });
+});
+
+// ── QRPaymentService.createPaymentRequest ────────────────────────────────────
+
+describe('QRPaymentService.createPaymentRequest', () => {
+  it('creates a request and returns a sep007Uri for XLM', async () => {
+    const { service } = makeService();
+
+    const result = await service.createPaymentRequest({
+      merchantId: 'mch_1',
+      destinationAddress: VALID_ADDRESS,
+      amount: '25.00',
+      asset: 'XLM',
+      network: 'testnet',
+    });
+
+    expect(result.sep007Uri).toMatch(/^web\+stellar:pay\?/);
+    expect(result.sep007Uri).toContain('amount=25.00');
+    expect(result.sep007Uri).not.toContain('asset_code');
+  });
+
+  it('creates a request and returns a sep007Uri for USDC with issuer', async () => {
+    const { service } = makeService();
+
+    const result = await service.createPaymentRequest({
+      merchantId: 'mch_1',
+      destinationAddress: VALID_ADDRESS,
+      amount: '100.00',
+      asset: 'USDC',
+      issuer: VALID_ISSUER,
+      network: 'mainnet',
+    });
+
+    expect(result.sep007Uri).toContain('asset_code=USDC');
+    expect(result.sep007Uri).toContain(
+      `network_passphrase=${encodeURIComponent(STELLAR_NETWORK_PASSPHRASES.mainnet)}`,
+    );
+  });
+
+  it('stores the request in the backing store', async () => {
+    const { service, store } = makeService();
+
+    const result = await service.createPaymentRequest({
+      merchantId: 'mch_2',
+      destinationAddress: VALID_ADDRESS,
+      amount: '5.00',
+      asset: 'XLM',
+      network: 'testnet',
+    });
+
+    expect(store.size).toBe(1);
+    const stored = await store.findById(result.request.id);
+    expect(stored).not.toBeNull();
+    expect(stored?.amount).toBe('5.00');
+  });
+
+  it('generates a unique ID for each request', async () => {
+    const { service } = makeService();
+
+    const r1 = await service.createPaymentRequest({
+      merchantId: 'mch_1',
+      destinationAddress: VALID_ADDRESS,
+      amount: '1.00',
+      asset: 'XLM',
+      network: 'testnet',
+    });
+    const r2 = await service.createPaymentRequest({
+      merchantId: 'mch_1',
+      destinationAddress: VALID_ADDRESS,
+      amount: '2.00',
+      asset: 'XLM',
+      network: 'testnet',
+    });
+
+    expect(r1.request.id).not.toBe(r2.request.id);
+  });
+
+  it('uses a caller-supplied ID when provided', async () => {
+    const { service } = makeService();
+
+    const result = await service.createPaymentRequest({
+      id: 'custom_id_123',
+      merchantId: 'mch_1',
+      destinationAddress: VALID_ADDRESS,
+      amount: '1.00',
+      asset: 'XLM',
+      network: 'testnet',
+    });
+
+    expect(result.request.id).toBe('custom_id_123');
+  });
+
+  it('sets expiresAt when ttlMs is given', async () => {
+    const ts = 1_700_000_000_000;
+    const { service } = makeService(ts);
+
+    const result = await service.createPaymentRequest({
+      merchantId: 'mch_1',
+      destinationAddress: VALID_ADDRESS,
+      amount: '1.00',
+      asset: 'XLM',
+      network: 'testnet',
+      ttlMs: 60_000,
+    });
+
+    expect(result.request.expiresAt).toBe(ts + 60_000);
+  });
+
+  it('returns a qrDataUri that decodes to the sep007Uri', async () => {
+    const { service } = makeService();
+
+    const result = await service.createPaymentRequest({
+      merchantId: 'mch_1',
+      destinationAddress: VALID_ADDRESS,
+      amount: '7.77',
+      asset: 'XLM',
+      network: 'testnet',
+    });
+
+    const b64 = result.qrDataUri.replace('data:text/plain;base64,', '');
+    const decoded = Buffer.from(b64, 'base64').toString('utf8');
+    expect(decoded).toBe(result.sep007Uri);
+  });
+
+  it('includes memo in the URI when memo is provided', async () => {
+    const { service } = makeService();
+
+    const result = await service.createPaymentRequest({
+      merchantId: 'mch_1',
+      destinationAddress: VALID_ADDRESS,
+      amount: '1.00',
+      asset: 'XLM',
+      memo: 'invoice-007',
+      network: 'testnet',
+    });
+
+    expect(result.sep007Uri).toContain(`memo=${encodeURIComponent('invoice-007')}`);
+  });
+});
+
+// ── QRPaymentService.validatePaymentRequest ───────────────────────────────────
+
+describe('QRPaymentService.validatePaymentRequest', () => {
+  it('returns valid=true for an active (non-expired) request', async () => {
+    const ts = 1_700_000_000_000;
+    const { service } = makeService(ts);
+
+    const { request } = await service.createPaymentRequest({
+      merchantId: 'mch_1',
+      destinationAddress: VALID_ADDRESS,
+      amount: '1.00',
+      asset: 'XLM',
+      network: 'testnet',
+      ttlMs: 300_000,
+    });
+
+    const result = await service.validatePaymentRequest(request.id);
+    expect(result.valid).toBe(true);
+    expect(result.reason).toBeUndefined();
+  });
+
+  it('returns valid=true for a request with no expiry', async () => {
+    const { service } = makeService();
+
+    const { request } = await service.createPaymentRequest({
+      merchantId: 'mch_1',
+      destinationAddress: VALID_ADDRESS,
+      amount: '1.00',
+      asset: 'XLM',
+      network: 'testnet',
+      // no ttlMs → no expiresAt
+    });
+
+    const result = await service.validatePaymentRequest(request.id);
+    expect(result.valid).toBe(true);
+  });
+
+  it('returns valid=false with reason "expired" for an expired request', async () => {
+    const ts = 1_700_000_000_000;
+    const { service } = makeService(ts);
+
+    // Create with a tiny TTL that has already passed.
+    const { request } = await service.createPaymentRequest({
+      merchantId: 'mch_1',
+      destinationAddress: VALID_ADDRESS,
+      amount: '1.00',
+      asset: 'XLM',
+      network: 'testnet',
+      ttlMs: -1_000, // expiresAt will be in the past
+    });
+
+    const result = await service.validatePaymentRequest(request.id);
+    expect(result.valid).toBe(false);
+    expect(result.reason).toBe('expired');
+  });
+
+  it('returns valid=false with reason "not_found" for an unknown ID', async () => {
+    const { service } = makeService();
+
+    const result = await service.validatePaymentRequest('does_not_exist');
+    expect(result.valid).toBe(false);
+    expect(result.reason).toBe('not_found');
+  });
+});
+
+// ── QRPaymentService.getPaymentRequest ───────────────────────────────────────
+
+describe('QRPaymentService.getPaymentRequest', () => {
+  it('returns null for an unknown ID', async () => {
+    const { service } = makeService();
+    const result = await service.getPaymentRequest('nonexistent');
+    expect(result).toBeNull();
+  });
+
+  it('returns the correct request when it exists', async () => {
+    const { service } = makeService();
+
+    const { request } = await service.createPaymentRequest({
+      merchantId: 'mch_5',
+      destinationAddress: VALID_ADDRESS,
+      amount: '99.99',
+      asset: 'USDC',
+      issuer: VALID_ISSUER,
+      memo: 'ref-789',
+      network: 'mainnet',
+    });
+
+    const fetched = await service.getPaymentRequest(request.id);
+    expect(fetched).not.toBeNull();
+    expect(fetched?.merchantId).toBe('mch_5');
+    expect(fetched?.amount).toBe('99.99');
+    expect(fetched?.asset).toBe('USDC');
+    expect(fetched?.memo).toBe('ref-789');
+    expect(fetched?.network).toBe('mainnet');
+  });
+});
+
+// ── InMemoryQRPaymentStore ────────────────────────────────────────────────────
+
+describe('InMemoryQRPaymentStore', () => {
+  it('saves and retrieves a request by ID', async () => {
+    const store = new InMemoryQRPaymentStore();
+    const req = makeBaseRequest({ id: 'store_test_1' });
+
+    await store.save(req);
+    const found = await store.findById('store_test_1');
+
+    expect(found).toEqual(req);
+  });
+
+  it('returns null for an ID that was never saved', async () => {
+    const store = new InMemoryQRPaymentStore();
+    expect(await store.findById('missing')).toBeNull();
+  });
+
+  it('clears all records', async () => {
+    const store = new InMemoryQRPaymentStore();
+    await store.save(makeBaseRequest({ id: 'a' }));
+    await store.save(makeBaseRequest({ id: 'b' }));
+
+    store.clear();
+    expect(store.size).toBe(0);
+  });
+});
diff --git a/backend/services/stellar/qrPaymentService.ts b/backend/services/stellar/qrPaymentService.ts
new file mode 100644
index 00000000..ebc34b04
--- /dev/null
+++ b/backend/services/stellar/qrPaymentService.ts
@@ -0,0 +1,250 @@
+/**
+ * QR code payment requests for in-person checkout (Issue #1714).
+ *
+ * Builds SEP-0007 `web+stellar:pay` URIs and encodes them as base64 data-URIs
+ * that a client can render as a QR code.  No external QR library is required —
+ * the client already knows how to turn a data-URI into a scannable image.
+ *
+ * SEP-0007 spec: https://github.com/stellar/stellar-protocol/blob/master/ecosystem/sep-0007.md
+ */
+
+// ── Network passphrases ───────────────────────────────────────────────────────
+
+export const STELLAR_NETWORK_PASSPHRASES = {
+  testnet: 'Test SDF Network ; September 2015',
+  mainnet: 'Public Global Stellar Network ; September 2015',
+} as const;
+
+// ── Types ─────────────────────────────────────────────────────────────────────
+
+export interface QRPaymentRequest {
+  /** Unique request ID (caller-supplied or auto-generated). */
+  id: string;
+  merchantId: string;
+  /** Stellar G… destination address. */
+  destinationAddress: string;
+  /** Payment amount as a string to avoid IEEE-754 precision loss. */
+  amount: string;
+  /** Asset code, e.g. 'XLM' or 'USDC'. */
+  asset: string;
+  /** Stellar issuer address for non-native assets. */
+  issuer?: string;
+  /** Optional SEP-0007 memo text. */
+  memo?: string;
+  network: 'testnet' | 'mainnet';
+  /** Unix timestamp (ms) when the request was created. */
+  createdAt: number;
+  /** Unix timestamp (ms) after which the request should be considered expired. */
+  expiresAt?: number;
+}
+
+export interface CreateQRInput {
+  merchantId: string;
+  destinationAddress: string;
+  amount: string;
+  asset: string;
+  issuer?: string;
+  memo?: string;
+  network: 'testnet' | 'mainnet';
+  /** Optional TTL in milliseconds from now. */
+  ttlMs?: number;
+  /** Override the auto-generated ID. */
+  id?: string;
+}
+
+export interface QRPaymentResult {
+  request: QRPaymentRequest;
+  /**
+   * SEP-0007 URI, e.g.
+   * `web+stellar:pay?destination=G…&amount=10.00&memo=order-42&network_passphrase=…`
+   */
+  sep007Uri: string;
+  /**
+   * `data:text/plain;base64,<base64(sep007Uri)>` — the client renders this as
+   * a QR code image using any standard QR library or canvas API.
+   */
+  qrDataUri: string;
+}
+
+export interface ValidationResult {
+  valid: boolean;
+  reason?: string;
+}
+
+// ── Store interface ───────────────────────────────────────────────────────────
+
+export interface QRPaymentStore {
+  save(request: QRPaymentRequest): Promise<void>;
+  findById(id: string): Promise<QRPaymentRequest | null>;
+}
+
+// ── In-memory store implementation ───────────────────────────────────────────
+
+export class InMemoryQRPaymentStore implements QRPaymentStore {
+  private readonly store = new Map<string, QRPaymentRequest>();
+
+  async save(request: QRPaymentRequest): Promise<void> {
+    this.store.set(request.id, { ...request });
+  }
+
+  async findById(id: string): Promise<QRPaymentRequest | null> {
+    return this.store.get(id) ?? null;
+  }
+
+  /** Test helper: clear all records. */
+  clear(): void {
+    this.store.clear();
+  }
+
+  /** Test helper: access the underlying map directly. */
+  get size(): number {
+    return this.store.size;
+  }
+}
+
+// ── Clock abstraction (injectable for testing) ───────────────────────────────
+
+export interface Clock {
+  now(): number;
+}
+
+export class SystemClock implements Clock {
+  now(): number {
+    return Date.now();
+  }
+}
+
+// ── ID generator abstraction (injectable for testing) ────────────────────────
+
+export interface IdGenerator {
+  generate(): string;
+}
+
+export class RandomIdGenerator implements IdGenerator {
+  generate(): string {
+    return `qr_${Math.random().toString(36).slice(2, 11)}_${Date.now()}`;
+  }
+}
+
+// ── SEP-0007 URI builder (pure function) ─────────────────────────────────────
+
+/**
+ * Builds a SEP-0007 `web+stellar:pay` URI from the given payment request.
+ *
+ * Rules:
+ * - For XLM (native asset): `asset_code` and `asset_issuer` are omitted.
+ * - For non-native assets: `asset_code` and optionally `asset_issuer` are
+ *   included.
+ * - All parameter values are URL-encoded.
+ * - `network_passphrase` is always included so wallets know which network to
+ *   use without out-of-band configuration.
+ */
+export function buildSep007Uri(request: QRPaymentRequest): string {
+  // Build pairs manually so we can use encodeURIComponent (RFC 3986, %20 for
+  // spaces) instead of URLSearchParams which uses form-encoding (+ for spaces).
+  const pairs: [string, string][] = [];
+
+  pairs.push(['destination', request.destinationAddress]);
+  pairs.push(['amount', request.amount]);
+
+  const isNative = request.asset.toUpperCase() === 'XLM';
+  if (!isNative) {
+    pairs.push(['asset_code', request.asset]);
+    if (request.issuer) {
+      pairs.push(['asset_issuer', request.issuer]);
+    }
+  }
+
+  if (request.memo) {
+    pairs.push(['memo', request.memo]);
+  }
+
+  pairs.push(['network_passphrase', STELLAR_NETWORK_PASSPHRASES[request.network]]);
+
+  const qs = pairs.map(([k, v]) => `${encodeURIComponent(k)}=${encodeURIComponent(v)}`).join('&');
+  return `web+stellar:pay?${qs}`;
+}
+
+/**
+ * Encodes a SEP-0007 URI as a base64 data-URI.
+ * The data-URI type is `text/plain` — clients use the decoded string directly
+ * as the QR code payload, which Stellar wallets read and parse.
+ */
+export function buildQrDataUri(sep007Uri: string): string {
+  const encoded = Buffer.from(sep007Uri, 'utf8').toString('base64');
+  return `data:text/plain;base64,${encoded}`;
+}
+
+// ── Service ───────────────────────────────────────────────────────────────────
+
+/**
+ * QRPaymentService — creates SEP-0007 payment requests and encodes them as
+ * base64 data-URIs suitable for QR code rendering.
+ *
+ * Dependencies are injectable so the service is easily tested without I/O.
+ */
+export class QRPaymentService {
+  constructor(
+    private readonly store: QRPaymentStore,
+    private readonly clock: Clock = new SystemClock(),
+    private readonly idGen: IdGenerator = new RandomIdGenerator(),
+  ) {}
+
+  /**
+   * Creates a new QR payment request, persists it and returns the SEP-0007 URI
+   * together with the base64 data-URI.
+   */
+  async createPaymentRequest(input: CreateQRInput): Promise<QRPaymentResult> {
+    const now = this.clock.now();
+
+    const request: QRPaymentRequest = {
+      id: input.id ?? this.idGen.generate(),
+      merchantId: input.merchantId,
+      destinationAddress: input.destinationAddress,
+      amount: input.amount,
+      asset: input.asset,
+      issuer: input.issuer,
+      memo: input.memo,
+      network: input.network,
+      createdAt: now,
+      expiresAt: input.ttlMs !== undefined ? now + input.ttlMs : undefined,
+    };
+
+    await this.store.save(request);
+
+    const sep007Uri = buildSep007Uri(request);
+    const qrDataUri = buildQrDataUri(sep007Uri);
+
+    return { request, sep007Uri, qrDataUri };
+  }
+
+  /**
+   * Validates whether a stored QR payment request is still usable.
+   *
+   * Returns:
+   * - `{ valid: true }` — request exists and has not expired.
+   * - `{ valid: false, reason: 'not_found' }` — no request with this ID.
+   * - `{ valid: false, reason: 'expired' }` — request exists but `expiresAt`
+   *   is in the past.
+   */
+  async validatePaymentRequest(id: string): Promise<ValidationResult> {
+    const request = await this.store.findById(id);
+
+    if (!request) {
+      return { valid: false, reason: 'not_found' };
+    }
+
+    if (request.expiresAt !== undefined && request.expiresAt < this.clock.now()) {
+      return { valid: false, reason: 'expired' };
+    }
+
+    return { valid: true };
+  }
+
+  /**
+   * Retrieves a stored QR payment request by ID, or `null` if not found.
+   */
+  async getPaymentRequest(id: string): Promise<QRPaymentRequest | null> {
+    return this.store.findById(id);
+  }
+}