diff --git a/README.md b/README.md
index 2d9f047..0efedf6 100644
--- a/README.md
+++ b/README.md
@@ -359,10 +359,14 @@ below. Nothing is installed without someone clicking.
   explain.
 
   **Song Key** is one value, as large as the tile allows: the key of the item
-  ProPresenter has live, set as a note (B♭, F♯m), with the song's name and the
-  next key under it — both switches, as is the colour. When the feed that
-  picks the item is gone the key stays up, faded, and the tile's dot says so
-  rather than pretending to be current.
+  ProPresenter has live, with the song's name and the next key under it — both
+  switches, as is the colour. When the feed that picks the item is gone the key
+  stays up, faded, and the tile's dot says so rather than pretending to be
+  current.
+
+  Keys are written as notes wherever the module shows one: Planning Center's
+  `Bb` and `F#m` read as B♭ and F♯m, on the Plan tile's item badge and in the
+  Song Key tile alike.
 
   **Teams** shows the same plan's team and position assignments — each team
   as a band of its people, with their photo (fetched through ProdDash, never
diff --git a/modules/pco-plan/client.js b/modules/pco-plan/client.js
index ca2f29d..685bc75 100644
--- a/modules/pco-plan/client.js
+++ b/modules/pco-plan/client.js
@@ -14,6 +14,7 @@
 
 import createTeams from "./teams-client.js";
 import createKey from "./key-client.js";
+import { prettyKey } from "./key-notation.js";
 
 const REFRESH_SVG = '<svg viewBox="0 0 24 24" width="14" height="14" fill="none" stroke="currentColor" stroke-width="2.2" stroke-linecap="round" stroke-linejoin="round"><path d="M21 12a9 9 0 1 1-2.64-6.36"/><path d="M21 3v6h-6"/></svg>';
 
@@ -369,7 +370,8 @@ function createPlan({ root, moduleApi }) {
       if (on('showKey') && item.keyName) {
         const key = document.createElement('span');
         key.className = 'pp-key';
-        key.textContent = item.keyName;
+        // B♭, F♯m — the same notation the Song Key tile uses.
+        key.textContent = prettyKey(item.keyName);
         titleLine.appendChild(key);
       }
       if (on('showNowIndicator')) {
diff --git a/modules/pco-plan/key-client.js b/modules/pco-plan/key-client.js
index eda8e5b..1297227 100644
--- a/modules/pco-plan/key-client.js
+++ b/modules/pco-plan/key-client.js
@@ -4,6 +4,8 @@
    streamed state the Plan tile does, so it needs no connection of its own;
    which item is current comes from the ProPresenter module, as ever. */
 
+import { parseKey, prettyKey } from "./key-notation.js";
+
 export default function createKey({ root, moduleApi }) {
   let state = null;
   let stream = null;
@@ -69,13 +71,7 @@ export default function createKey({ root, moduleApi }) {
     }
     if (!state.live.ppReachable) return moduleApi.setStatus('error', 'ProPresenter unreachable — showing the last item');
     if (!item) return moduleApi.setStatus('ok', 'Waiting for an item to go live');
-    moduleApi.setStatus('ok', `${titleOf(item)}${item.keyName ? ` — ${item.keyName}` : ' — no key in the plan'}`);
-  }
-
-  /** "Bb" → "B♭", "F#m" → "F♯m" — for the plain-text line under the key. */
-  function prettyKey(text) {
-    const match = /^([A-G])([#b])(.*)$/.exec(String(text || '').trim());
-    return match ? `${match[1]}${match[2] === '#' ? '♯' : '♭'}${match[3]}` : String(text || '');
+    moduleApi.setStatus('ok', `${titleOf(item)}${item.keyName ? ` — ${prettyKey(item.keyName)}` : ' — no key in the plan'}`);
   }
 
   /**
@@ -84,23 +80,22 @@ export default function createKey({ root, moduleApi }) {
    */
   function drawKey(text) {
     keyEl.innerHTML = '';
-    const match = /^([A-G])([#b♯♭]?)(.*)$/.exec(String(text).trim());
-    if (!match) {
+    const parts = parseKey(text);
+    if (!parts) {
       keyEl.textContent = text;
       return;
     }
-    const [, note, accidental, rest] = match;
-    keyEl.appendChild(document.createTextNode(note));
-    if (accidental) {
-      const sup = document.createElement('span');
-      sup.className = 'pk-accidental';
-      sup.textContent = accidental === '#' ? '♯' : accidental === 'b' ? '♭' : accidental;
-      keyEl.appendChild(sup);
+    keyEl.appendChild(document.createTextNode(parts.note));
+    if (parts.accidental) {
+      const acc = document.createElement('span');
+      acc.className = 'pk-accidental';
+      acc.textContent = parts.accidental;
+      keyEl.appendChild(acc);
     }
-    if (rest) {
+    if (parts.quality) {
       const tail = document.createElement('span');
       tail.className = 'pk-quality';
-      tail.textContent = rest;
+      tail.textContent = parts.quality;
       keyEl.appendChild(tail);
     }
   }
diff --git a/modules/pco-plan/key-notation.js b/modules/pco-plan/key-notation.js
new file mode 100644
index 0000000..f5b7dba
--- /dev/null
+++ b/modules/pco-plan/key-notation.js
@@ -0,0 +1,25 @@
+/* PCO Plan — how a song key is written.
+
+   Planning Center stores keys as typed: "Bb", "F#m", "Ab". Every tile in this
+   module shows them as notes instead — B♭, F♯m, A♭ — so the plan, the badge
+   on an item and the Song Key tile all agree. Shared rather than repeated
+   because the day one of them changes, they all should. */
+
+/** "F#m" → { note: 'F', accidental: '♯', quality: 'm' }; anything odd → null. */
+export function parseKey(raw) {
+  const match = /^([A-G])\s*([#b♯♭]?)\s*(.*)$/.exec(String(raw || '').trim());
+  if (!match) return null;
+  const [, note, accidental, quality] = match;
+  return {
+    note,
+    accidental: accidental === '#' ? '♯' : accidental === 'b' ? '♭' : accidental,
+    quality: quality.trim(),
+  };
+}
+
+/** The same thing as one string, for a badge or a caption. */
+export function prettyKey(raw) {
+  const parts = parseKey(raw);
+  if (!parts) return String(raw || '').trim();
+  return `${parts.note}${parts.accidental}${parts.quality}`;
+}