diff --git a/src/quartermaster/routes.py b/src/quartermaster/routes.py
index 926eb60..b9283c4 100644
--- a/src/quartermaster/routes.py
+++ b/src/quartermaster/routes.py
@@ -107,13 +107,14 @@ def create_entry(
     request: Request,
     name: str = Form(...),
     amount: str = Form(...),
+    notes: str | None = Form(None),
     db: Session = Depends(get_session),
 ) -> HTMLResponse:
     clean_name = name.strip()
     if not clean_name:
         raise HTTPException(status_code=400, detail="name is required")
     parsed = _parse_amount(amount)
-    service.add_entry(db, section, clean_name, parsed)
+    service.add_entry(db, section, clean_name, parsed, notes=notes)
     response = _render_section(request, db, section)
     extras: list[HTMLResponse] = [
         _render_zero(request, db),
@@ -143,6 +144,19 @@ def remove_entry(
     return _append_oob(response, *extras)
 
 
+@router.post("/entries/{entry_id}/notes", response_class=HTMLResponse)
+def update_entry_notes(
+    entry_id: int,
+    request: Request,
+    notes: str | None = Form(None),
+    db: Session = Depends(get_session),
+) -> HTMLResponse:
+    updated = service.set_entry_notes(db, entry_id, notes)
+    if updated is None:
+        raise HTTPException(status_code=404, detail="entry not found")
+    return _render_section(request, db, updated.section)
+
+
 @router.post("/debt-target", response_class=HTMLResponse)
 def update_debt_target(
     request: Request,
diff --git a/src/quartermaster/routes_month.py b/src/quartermaster/routes_month.py
index 8faa748..b6ee5e2 100644
--- a/src/quartermaster/routes_month.py
+++ b/src/quartermaster/routes_month.py
@@ -164,6 +164,7 @@ def add_month_entry(
     request: Request,
     name: str = Form(...),
     planned: str = Form(...),
+    notes: str | None = Form(None),
     db: Session = Depends(get_session),
 ) -> HTMLResponse:
     month = _require_month(db, year_month)
@@ -171,7 +172,7 @@ def add_month_entry(
     if not clean_name:
         raise HTTPException(status_code=400, detail="name is required")
     month_service.add_month_entry(
-        db, month, section, clean_name, _parse_amount(planned)
+        db, month, section, clean_name, _parse_amount(planned), notes=notes
     )
     db.refresh(month)
     return _append_oob(
@@ -210,6 +211,7 @@ def update_month_entry(
     name: str | None = Form(None),
     planned: str | None = Form(None),
     applied: str | None = Form(None),
+    notes: str | None = Form(None),
     db: Session = Depends(get_session),
 ) -> HTMLResponse:
     month = _require_month(db, year_month)
@@ -220,14 +222,14 @@ def update_month_entry(
             raise HTTPException(status_code=400, detail="name must not be empty")
     parsed_planned = _parse_amount(planned) if planned is not None else None
     parsed_applied = _parse_amount(applied) if applied is not None else None
-    updated = month_service.update_month_entry(
-        db,
-        month,
-        entry_id,
+    kwargs: dict = dict(
         name=clean_name,
         planned=parsed_planned,
         applied=parsed_applied,
     )
+    if notes is not None:
+        kwargs["notes"] = notes
+    updated = month_service.update_month_entry(db, month, entry_id, **kwargs)
     if updated is None:
         raise HTTPException(status_code=404, detail="entry not found")
     db.refresh(month)
diff --git a/src/quartermaster/static/app.css b/src/quartermaster/static/app.css
index 8a9fb97..5106d1e 100644
--- a/src/quartermaster/static/app.css
+++ b/src/quartermaster/static/app.css
@@ -111,6 +111,37 @@ tr.add-row td {
 
 .muted { color: var(--muted); font-style: italic; }
 
+tr.entry-notes-row td {
+  padding: 0 0.5rem 0.35rem;
+  border-bottom: 1px solid var(--rule);
+}
+
+.notes-input {
+  width: 100%;
+  padding: 0.2rem 0.4rem;
+  font-size: 0.85rem;
+  color: var(--muted);
+  background: transparent;
+  border: none;
+  border-bottom: 1px dashed transparent;
+}
+
+.notes-input:hover,
+.notes-input:focus {
+  border-bottom-color: var(--rule);
+  outline: none;
+}
+
+.notes-input:not(:placeholder-shown) {
+  color: var(--ink);
+  font-style: italic;
+}
+
+.add-form .add-notes {
+  grid-column: 1 / -1;
+  font-size: 0.85rem;
+}
+
 button.delete {
   background: transparent;
   border: none;
diff --git a/src/quartermaster/templates/partials/month_section.html b/src/quartermaster/templates/partials/month_section.html
index 922316d..88b6d6f 100644
--- a/src/quartermaster/templates/partials/month_section.html
+++ b/src/quartermaster/templates/partials/month_section.html
@@ -68,6 +68,22 @@
             >&times;</button>
           </td>
         </tr>
+        <tr class="entry-notes-row">
+          <td colspan="4">
+            <input
+              class="notes-input"
+              type="text"
+              name="notes"
+              value="{{ row.entry.notes or '' }}"
+              placeholder="notes..."
+              hx-post="/month/{{ month.year_month }}/entries/{{ row.entry.id }}"
+              hx-trigger="change"
+              hx-target="#section-{{ section.section.value }}"
+              hx-swap="outerHTML"
+              aria-label="Notes for {{ row.entry.name }}"
+            >
+          </td>
+        </tr>
       {% else %}
         <tr class="empty"><td colspan="4">No entries.</td></tr>
       {% endfor %}
@@ -83,6 +99,7 @@
             <input type="text" name="name" placeholder="Name" required>
             <input type="number" name="planned" step="0.01" min="0" placeholder="Planned" required>
             <button type="submit">Add</button>
+            <input class="notes-input add-notes" type="text" name="notes" placeholder="notes (optional)">
           </form>
         </td>
       </tr>
diff --git a/src/quartermaster/templates/partials/section.html b/src/quartermaster/templates/partials/section.html
index 59210c8..8abe715 100644
--- a/src/quartermaster/templates/partials/section.html
+++ b/src/quartermaster/templates/partials/section.html
@@ -22,6 +22,22 @@
             >&times;</button>
           </td>
         </tr>
+        <tr class="entry-notes-row">
+          <td colspan="3">
+            <input
+              class="notes-input"
+              type="text"
+              name="notes"
+              value="{{ entry.notes or '' }}"
+              placeholder="notes..."
+              hx-post="/entries/{{ entry.id }}/notes"
+              hx-trigger="change"
+              hx-target="#section-{{ section.section.value }}"
+              hx-swap="outerHTML"
+              aria-label="Notes for {{ entry.name }}"
+            >
+          </td>
+        </tr>
       {% else %}
         <tr class="empty"><td colspan="3">No entries yet.</td></tr>
       {% endfor %}
@@ -37,6 +53,7 @@
             <input type="text" name="name" placeholder="Name" required>
             <input type="number" name="amount" step="0.01" min="0" placeholder="0.00" required>
             <button type="submit">Add</button>
+            <input class="notes-input add-notes" type="text" name="notes" placeholder="notes (optional)">
           </form>
         </td>
       </tr>