diff --git a/.changeset/brave-decimals-clean.md b/.changeset/brave-decimals-clean.md
new file mode 100644
index 0000000..b9bf21c
--- /dev/null
+++ b/.changeset/brave-decimals-clean.md
@@ -0,0 +1,5 @@
+---
+'@inflowpayai/inflow': patch
+---
+
+Normalize balance decimal response strings before rendering CLI output.
diff --git a/packages/core/src/resources/balance.ts b/packages/core/src/resources/balance.ts
index ca7c532..f1d5eca 100644
--- a/packages/core/src/resources/balance.ts
+++ b/packages/core/src/resources/balance.ts
@@ -2,6 +2,7 @@ import { type InflowOptions, type ResolvedInflowSdkConfig, resolveInflowSdkConfi
 import { InflowApiError } from '../errors.js';
 import type { Balance } from '../types/index.js';
 import { InflowApiClient } from '../utils/api-client.js';
+import { normalizeDecimalString } from '../utils/decimal.js';
 import { redactRawBody } from '../utils/redact.js';
 import type { IBalanceResource } from './interfaces.js';
 
@@ -31,6 +32,9 @@ export class BalanceResource implements IBalanceResource {
       );
     }
     const body = data as BalancesResponse | null;
-    return body?.balances ?? [];
+    return (body?.balances ?? []).map((balance) => ({
+      ...balance,
+      available: normalizeDecimalString(balance.available),
+    }));
   }
 }
diff --git a/packages/core/src/utils/decimal.ts b/packages/core/src/utils/decimal.ts
new file mode 100644
index 0000000..59736b5
--- /dev/null
+++ b/packages/core/src/utils/decimal.ts
@@ -0,0 +1,24 @@
+const PLAIN_DECIMAL_RE = /^-?\d+(?:\.\d+)?$/u;
+
+/**
+ * Normalize server decimal response strings without converting through `Number`, so precision is preserved and
+ * exponential notation is never introduced. Non-plain forms are returned unchanged.
+ */
+export function normalizeDecimalString(value: string): string {
+  if (!PLAIN_DECIMAL_RE.test(value)) return value;
+
+  const negative = value.startsWith('-');
+  const unsigned = negative ? value.slice(1) : value;
+  const [rawInteger = '0', rawFraction] = unsigned.split('.');
+  const integer = stripLeadingZeros(rawInteger);
+  const fraction = rawFraction?.replace(/0+$/u, '') ?? '';
+
+  if (integer === '0' && fraction.length === 0) return '0';
+  const sign = negative ? '-' : '';
+  return fraction.length === 0 ? `${sign}${integer}` : `${sign}${integer}.${fraction}`;
+}
+
+function stripLeadingZeros(value: string): string {
+  const stripped = value.replace(/^0+/u, '');
+  return stripped.length === 0 ? '0' : stripped;
+}
diff --git a/packages/core/test/unit/resources/balance.test.ts b/packages/core/test/unit/resources/balance.test.ts
index b717a25..1530465 100644
--- a/packages/core/test/unit/resources/balance.test.ts
+++ b/packages/core/test/unit/resources/balance.test.ts
@@ -1,4 +1,5 @@
 import { afterAll, afterEach, beforeAll, describe, expect, it } from 'vitest';
+import { http, HttpResponse } from 'msw';
 import { InflowApiError } from '../../../src/errors.js';
 import { BalanceResource } from '../../../src/resources/balance.js';
 import { BASE_URL, balancesHappy, balancesEmpty, balances500 } from '../fixtures/handlers.js';
@@ -24,6 +25,48 @@ describe('BalanceResource', () => {
     ]);
   });
 
+  it('normalizes server decimal strings without scientific notation', async () => {
+    server.use(
+      http.get(`${BASE_URL}/v1/balances`, () =>
+        HttpResponse.json({
+          balances: [
+            { available: '100.500000000000000000', currency: 'USDC' },
+            { available: '0.000000000000000000', currency: 'USD' },
+            { available: '0.000001000000000000', currency: 'PYUSD' },
+          ],
+        }),
+      ),
+    );
+    const r = new BalanceResource({
+      apiBaseUrl: BASE_URL,
+      accessToken: 'tk',
+    });
+    expect(await r.list()).toEqual([
+      { available: '100.5', currency: 'USDC' },
+      { available: '0', currency: 'USD' },
+      { available: '0.000001', currency: 'PYUSD' },
+    ]);
+  });
+
+  it('passes an AbortSignal through request options', async () => {
+    let signalSeen = false;
+    server.use(
+      http.get(`${BASE_URL}/v1/balances`, ({ request }) => {
+        signalSeen = request.signal instanceof AbortSignal;
+        return HttpResponse.json({
+          balances: [{ available: '1.000000000000000000', currency: 'USDC' }],
+        });
+      }),
+    );
+    const r = new BalanceResource({
+      apiBaseUrl: BASE_URL,
+      accessToken: 'tk',
+    });
+    const controller = new AbortController();
+    await expect(r.list({ signal: controller.signal })).resolves.toEqual([{ available: '1', currency: 'USDC' }]);
+    expect(signalSeen).toBe(true);
+  });
+
   it('returns [] for an empty server response', async () => {
     server.use(balancesEmpty);
     const r = new BalanceResource({
@@ -33,6 +76,15 @@ describe('BalanceResource', () => {
     expect(await r.list()).toEqual([]);
   });
 
+  it('returns [] when the server response body is null', async () => {
+    server.use(http.get(`${BASE_URL}/v1/balances`, () => HttpResponse.json(null)));
+    const r = new BalanceResource({
+      apiBaseUrl: BASE_URL,
+      accessToken: 'tk',
+    });
+    expect(await r.list()).toEqual([]);
+  });
+
   it('throws InflowApiError on 5xx after retries', async () => {
     server.use(balances500);
     const r = new BalanceResource({
diff --git a/packages/core/test/unit/utils/decimal.test.ts b/packages/core/test/unit/utils/decimal.test.ts
new file mode 100644
index 0000000..1d901f8
--- /dev/null
+++ b/packages/core/test/unit/utils/decimal.test.ts
@@ -0,0 +1,27 @@
+import { describe, expect, it } from 'vitest';
+
+import { normalizeDecimalString } from '../../../src/utils/decimal.js';
+
+describe('normalizeDecimalString', () => {
+  it('strips trailing fractional zeros without precision loss', () => {
+    expect(normalizeDecimalString('100.500000000000000000')).toBe('100.5');
+    expect(normalizeDecimalString('0.010000000000000000')).toBe('0.01');
+    expect(normalizeDecimalString('0.000001000000000000')).toBe('0.000001');
+  });
+
+  it('collapses whole-number decimals and negative zero', () => {
+    expect(normalizeDecimalString('00042')).toBe('42');
+    expect(normalizeDecimalString('42.000')).toBe('42');
+    expect(normalizeDecimalString('00042.000')).toBe('42');
+    expect(normalizeDecimalString('-0.000')).toBe('0');
+  });
+
+  it('preserves the sign on non-zero negative decimals', () => {
+    expect(normalizeDecimalString('-0012.3400')).toBe('-12.34');
+  });
+
+  it('leaves non-plain decimal strings untouched', () => {
+    expect(normalizeDecimalString('1e-6')).toBe('1e-6');
+    expect(normalizeDecimalString('1,000.00')).toBe('1,000.00');
+  });
+});