diff --git a/frontend/src/api/index.js b/frontend/src/api/index.js
index 5684439..db4dd23 100644
--- a/frontend/src/api/index.js
+++ b/frontend/src/api/index.js
@@ -1153,5 +1153,11 @@ export const printedpartsApi = {
   },
   deleteImage(printeditemid) {
     return api.delete(`/printedparts/items/${printeditemid}/image`)
+  },
+  restock(printeditemid, data) {
+    return api.post(`/printedparts/items/${printeditemid}/restock`, data)
+  },
+  adjust(printeditemid, data) {
+    return api.post(`/printedparts/items/${printeditemid}/adjust`, data)
   }
 }
diff --git a/frontend/src/views/printedparts/PrintedItemDetail.vue b/frontend/src/views/printedparts/PrintedItemDetail.vue
index 2c370a3..d14a158 100644
--- a/frontend/src/views/printedparts/PrintedItemDetail.vue
+++ b/frontend/src/views/printedparts/PrintedItemDetail.vue
@@ -19,6 +19,12 @@
             <p v-if="item.itemdescription">{{ item.itemdescription }}</p>
           </div>
           <div class="hero-actions">
+            <button class="btn btn-primary btn-sm" @click="openLedger('restock')">
+              Restock
+            </button>
+            <button class="btn btn-secondary btn-sm" @click="openLedger('adjust')">
+              Adjust
+            </button>
             <router-link :to="`/printedparts/${item.printeditemid}/edit`"
                          class="btn btn-secondary btn-sm">Edit</router-link>
           </div>
@@ -96,6 +102,30 @@
     </template>
 
     <div v-else class="card">Item not found</div>
+
+    <Modal v-model="ledgerOpen" :title="ledgerMode === 'restock' ? 'Restock' : 'Adjust count'">
+      <div v-if="ledgerError" class="error-message">{{ ledgerError }}</div>
+      <div class="form-group">
+        <label>{{ ledgerMode === 'restock' ? 'Quantity printed' : 'Change (+/-)' }}</label>
+        <input v-model.number="ledgerQuantity" type="number" class="form-control" />
+      </div>
+      <div v-if="ledgerMode === 'adjust'" class="form-group">
+        <label>Reason *</label>
+        <input v-model="ledgerReason" type="text" class="form-control"
+               placeholder="e.g., damaged parts scrapped, recount" />
+      </div>
+      <div class="form-group">
+        <label>Your badge / SSO *</label>
+        <input v-model="ledgerBadge" type="text" class="form-control"
+               placeholder="Scan badge or type SSO" />
+      </div>
+      <template #footer>
+        <button class="btn btn-primary" :disabled="ledgerSaving" @click="submitLedger">
+          {{ ledgerSaving ? 'Saving...' : 'Submit' }}
+        </button>
+        <button class="btn btn-secondary" @click="ledgerOpen = false">Cancel</button>
+      </template>
+    </Modal>
   </div>
 </template>
 
@@ -104,6 +134,7 @@ import { ref, onMounted } from 'vue'
 import { useRoute } from 'vue-router'
 import { printedpartsApi } from '../../api'
 import { withBase } from '../../utils/basePath'
+import Modal from '../../components/Modal.vue'
 
 const route = useRoute()
 const item = ref(null)
@@ -120,6 +151,50 @@ onMounted(async () => {
   }
 })
 
+const ledgerOpen = ref(false)
+const ledgerMode = ref('restock')
+const ledgerQuantity = ref(null)
+const ledgerReason = ref('')
+const ledgerBadge = ref('')
+const ledgerSaving = ref(false)
+const ledgerError = ref('')
+
+function openLedger(mode) {
+  ledgerMode.value = mode
+  ledgerQuantity.value = null
+  ledgerReason.value = ''
+  ledgerBadge.value = ''
+  ledgerError.value = ''
+  ledgerOpen.value = true
+}
+
+async function submitLedger() {
+  ledgerSaving.value = true
+  ledgerError.value = ''
+  try {
+    if (ledgerMode.value === 'restock') {
+      await printedpartsApi.restock(item.value.printeditemid, {
+        quantity: ledgerQuantity.value, badge: ledgerBadge.value
+      })
+    } else {
+      await printedpartsApi.adjust(item.value.printeditemid, {
+        quantitychange: ledgerQuantity.value,
+        reason: ledgerReason.value,
+        badge: ledgerBadge.value
+      })
+    }
+    ledgerOpen.value = false
+    const response = await printedpartsApi.get(item.value.printeditemid)
+    item.value = response.data.data
+  } catch (submitError) {
+    ledgerError.value =
+      submitError.response?.data?.data?.error?.message ||
+      submitError.response?.data?.error?.message || 'Submit failed'
+  } finally {
+    ledgerSaving.value = false
+  }
+}
+
 function formatDate(value) {
   if (!value) return '-'
   return new Date(value).toLocaleString()
diff --git a/plugins/printedparts/api/routes.py b/plugins/printedparts/api/routes.py
index 8cb7753..61d5d6b 100644
--- a/plugins/printedparts/api/routes.py
+++ b/plugins/printedparts/api/routes.py
@@ -210,3 +210,80 @@ def delete_item_image(item_id: int):
     item.imageurl = None
     db.session.commit()
     return success_response(item.to_dict(), message='Item image removed')
+
+
+# --- the ledger: restock and adjust (stage 6 gates with printedparts.restock)
+
+from ..models import PrintedItemTransaction
+from ..services.badges import BadgeError, resolve_badge
+
+
+def _ledger_write(item, transactiontype, quantitychange, sso, name, reason=None):
+    """Append a ledger row and move the cached quantity in ONE commit.
+
+    The single-commit invariant is what keeps quantityonhand equal to the
+    ledger sum; every write path must go through here.
+    """
+    item.quantityonhand += quantitychange
+    db.session.add(PrintedItemTransaction(
+        printeditemid=item.printeditemid,
+        transactiontype=transactiontype,
+        quantitychange=quantitychange,
+        employeesso=sso,
+        employeename=name,
+        reason=reason,
+    ))
+    db.session.commit()
+
+
+@printedparts_bp.route('/items/<int:item_id>/restock', methods=['POST'])
+@jwt_required()
+def restock_item(item_id: int):
+    """Add freshly printed stock. Body: {quantity, badge}."""
+    item = db.session.get(PrintedItem, item_id)
+    if not item or not item.isactive:
+        return error_response(ErrorCodes.NOT_FOUND,
+                              f'Printed item {item_id} not found', http_code=404)
+    data = request.get_json() or {}
+    quantity = data.get('quantity')
+    if not isinstance(quantity, int) or quantity < 1:
+        return error_response(ErrorCodes.VALIDATION_ERROR,
+                              'quantity must be a positive integer')
+    try:
+        sso, name = resolve_badge(data.get('badge'))
+    except BadgeError as badge_error:
+        return error_response(ErrorCodes.VALIDATION_ERROR, str(badge_error),
+                              http_code=422)
+    _ledger_write(item, 'restock', quantity, sso, name)
+    return success_response(item.to_dict(), message='Stock added')
+
+
+@printedparts_bp.route('/items/<int:item_id>/adjust', methods=['POST'])
+@jwt_required()
+def adjust_item(item_id: int):
+    """Correct the count (damage, recount). Body: {quantitychange, reason, badge}."""
+    item = db.session.get(PrintedItem, item_id)
+    if not item or not item.isactive:
+        return error_response(ErrorCodes.NOT_FOUND,
+                              f'Printed item {item_id} not found', http_code=404)
+    data = request.get_json() or {}
+    quantitychange = data.get('quantitychange')
+    if not isinstance(quantitychange, int) or quantitychange == 0:
+        return error_response(ErrorCodes.VALIDATION_ERROR,
+                              'quantitychange must be a non-zero integer')
+    reason = (data.get('reason') or '').strip()
+    if not reason:
+        return error_response(ErrorCodes.VALIDATION_ERROR,
+                              'reason is required for an adjustment')
+    if item.quantityonhand + quantitychange < 0:
+        return error_response(
+            ErrorCodes.VALIDATION_ERROR,
+            f'Adjustment would drive stock below zero '
+            f'(on hand: {item.quantityonhand})')
+    try:
+        sso, name = resolve_badge(data.get('badge'))
+    except BadgeError as badge_error:
+        return error_response(ErrorCodes.VALIDATION_ERROR, str(badge_error),
+                              http_code=422)
+    _ledger_write(item, 'adjust', quantitychange, sso, name, reason=reason)
+    return success_response(item.to_dict(), message='Stock adjusted')
diff --git a/plugins/printedparts/services/__init__.py b/plugins/printedparts/services/__init__.py
new file mode 100644
index 0000000..21758a6
--- /dev/null
+++ b/plugins/printedparts/services/__init__.py
@@ -0,0 +1 @@
+"""Printedparts plugin services."""
diff --git a/plugins/printedparts/services/badges.py b/plugins/printedparts/services/badges.py
new file mode 100644
index 0000000..81c7f43
--- /dev/null
+++ b/plugins/printedparts/services/badges.py
@@ -0,0 +1,69 @@
+"""Badge resolution for the printedparts plugin.
+
+Same input contract as the USB plugin (deliberately copied, not imported -
+cross-plugin imports break the shopdb.api-only contract):
+
+- all digits            -> an SSO typed or scanned directly
+- 0<digits>BZ           -> a physical badge wrapping a PayNo (keyboard-wedge
+                           scanners emit this shape)
+- anything else         -> unresolvable
+
+Names come from the employees plugin's self-hosted directory, looked up by
+SSO. The directory carries no PayNo column, so PayNo badges resolve only when
+the wrapped digits are themselves the SSO (true at sites whose badges encode
+the SSO); otherwise they fall to the unknown-badge policy.
+
+Policy (Setting printedparts_unknown_badge): 'deny' (default) rejects a badge
+with no directory match; 'allow' records the SSO with an empty name.
+"""
+
+import re
+
+from shopdb.api import Setting
+
+_PAYNO_BADGE = re.compile(r'^0(\d+)BZ$', re.IGNORECASE)
+
+
+class BadgeError(ValueError):
+    """Raised when a badge cannot be accepted under the site policy."""
+
+
+def _directory_name(sso):
+    """Best-effort display name from the employees plugin directory."""
+    try:
+        from plugins.employees.models import DirectoryEmployee
+        from shopdb.api import db
+        if sso and str(sso).isdigit():
+            employee = db.session.get(DirectoryEmployee, int(sso))
+            if employee:
+                return f'{employee.firstname} {employee.lastname}'.strip()
+    except Exception:
+        pass
+    return None
+
+
+def resolve_badge(badge):
+    """Return (sso, name) for a scanned badge, enforcing the site policy.
+
+    Raises BadgeError with a kiosk-displayable message when the badge shape is
+    unrecognized or the policy denies an unmatched badge.
+    """
+    badge = (badge or '').strip()
+    if not badge:
+        raise BadgeError('Scan or enter a badge')
+
+    if badge.isdigit():
+        sso = badge
+    else:
+        match = _PAYNO_BADGE.match(badge)
+        if not match:
+            raise BadgeError('Unrecognized badge format')
+        sso = match.group(1)
+
+    name = _directory_name(sso)
+    if name is None:
+        policy = (Setting.get('printedparts_unknown_badge') or 'deny').lower()
+        if policy != 'allow':
+            raise BadgeError('Badge not recognized - see the parts team')
+        return sso, ''
+    return sso, name
diff --git a/tests/test_plugins/test_printedparts_ledger.py b/tests/test_plugins/test_printedparts_ledger.py
new file mode 100644
index 0000000..21f4e55
--- /dev/null
+++ b/tests/test_plugins/test_printedparts_ledger.py
@@ -0,0 +1,121 @@
+"""Printedparts ledger + badge tests.
+
+The invariants that make the plugin trustworthy: itemcode minting, the
+single-commit cache==ledger rule, the below-zero guard, quantity edits
+forced through the ledger, and the badge contract (SSO digits, PayNo
+wrap, unknown-badge policy).
+"""
+
+import pytest
+
+from shopdb.api import db
+from shopdb.core.models import Setting
+from plugins.printedparts.models import PrintedItem, PrintedItemTransaction
+
+
+@pytest.fixture
+def item(app, db):
+    with app.app_context():
+        row = PrintedItem(itemcode='3DP-9001', itemname='Test clip',
+                          quantityonhand=0, lowstockthreshold=5)
+        db.session.add(row)
+        db.session.commit()
+        yield row.printeditemid
+
+
+@pytest.fixture
+def directory_employee(app):
+    with app.app_context():
+        from plugins.employees.models import DirectoryEmployee
+        if not db.session.get(DirectoryEmployee, 502000001):
+            db.session.add(DirectoryEmployee(
+                sso=502000001, firstname='Pat', lastname='Printer'))
+            db.session.commit()
+    return '502000001'
+
+
+def test_create_mints_itemcode(client, auth_headers):
+    response = client.post('/api/printedparts/items', json={'itemname': 'Bracket'},
+                           headers=auth_headers)
+    assert response.status_code == 201
+    data = response.get_json()['data']
+    assert data['itemcode'] == f"3DP-{data['printeditemid']:04d}"
+    assert data['quantityonhand'] == 0
+
+
+def test_update_refuses_quantity(client, auth_headers, item):
+    response = client.put(f'/api/printedparts/items/{item}',
+                          json={'quantityonhand': 50}, headers=auth_headers)
+    assert response.status_code == 400
+
+
+def test_restock_writes_ledger_and_cache(client, auth_headers, app, item,
+                                         directory_employee):
+    response = client.post(f'/api/printedparts/items/{item}/restock',
+                           json={'quantity': 10, 'badge': directory_employee},
+                           headers=auth_headers)
+    assert response.status_code == 200
+    assert response.get_json()['data']['quantityonhand'] == 10
+    with app.app_context():
+        rows = PrintedItemTransaction.query.filter_by(printeditemid=item).all()
+        assert len(rows) == 1
+        assert rows[0].transactiontype == 'restock'
+        assert rows[0].quantitychange == 10
+        assert rows[0].employeename == 'Pat Printer'
+        cached = db.session.get(PrintedItem, item).quantityonhand
+        assert cached == sum(r.quantitychange for r in rows)
+
+
+def test_payno_badge_shape_resolves(client, auth_headers, item,
+                                    directory_employee):
+    response = client.post(f'/api/printedparts/items/{item}/restock',
+                           json={'quantity': 1,
+                                 'badge': f'0{directory_employee}BZ'},
+                           headers=auth_headers)
+    assert response.status_code == 200
+
+
+def test_adjust_requires_reason_and_floors_at_zero(client, auth_headers, item,
+                                                   directory_employee):
+    no_reason = client.post(f'/api/printedparts/items/{item}/adjust',
+                            json={'quantitychange': -1,
+                                  'badge': directory_employee},
+                            headers=auth_headers)
+    assert no_reason.status_code == 400
+
+    below_zero = client.post(f'/api/printedparts/items/{item}/adjust',
+                             json={'quantitychange': -1, 'reason': 'test',
+                                   'badge': directory_employee},
+                             headers=auth_headers)
+    assert below_zero.status_code == 400
+
+
+def test_unknown_badge_denied_then_allowed_by_policy(client, auth_headers, app,
+                                                     item):
+    denied = client.post(f'/api/printedparts/items/{item}/restock',
+                         json={'quantity': 1, 'badge': '999999999'},
+                         headers=auth_headers)
+    assert denied.status_code == 422
+
+    with app.app_context():
+        Setting.set('printedparts_unknown_badge', 'allow',
+                    valuetype='string', category='printedparts')
+        db.session.commit()
+    try:
+        allowed = client.post(f'/api/printedparts/items/{item}/restock',
+                              json={'quantity': 1, 'badge': '999999999'},
+                              headers=auth_headers)
+        assert allowed.status_code == 200
+        assert allowed.get_json()['data']['quantityonhand'] == 1
+    finally:
+        with app.app_context():
+            Setting.set('printedparts_unknown_badge', 'deny',
+                        valuetype='string', category='printedparts')
+            db.session.commit()
+
+
+def test_anonymous_cannot_mutate(client, item):
+    assert client.post('/api/printedparts/items',
+                       json={'itemname': 'X'}).status_code == 401
+    assert client.post(f'/api/printedparts/items/{item}/restock',
+                       json={'quantity': 1, 'badge': '1'}).status_code == 401