If you own a pen phone, the most common case problem you will hit is not drop protection. It is a case that covers a millimetre too much of the S Pen silo, so the pen no longer seats fully — and a pen that does not seat fully does not charge.
Which phones store a pen and which do not
This trips people up, so it is worth being precise:
- Silo built into the phone: Galaxy Note 9, Note 10, Note 10 Plus, Note 20, Note 20 Ultra, and the Galaxy S22 Ultra, S23 Ultra, S24 Ultra and later Ultra models.
- Pen supported but no silo in the phone: Galaxy Z Fold 3 onward. The pen is a separate accessory and has to live somewhere — which is exactly why Fold cases with built-in pen holders exist.
- No pen support at all: base and Plus models of the S series, the A series, and the Z Flip line.
How a silo pen charges, and why clearance matters
Bluetooth-equipped S Pens — those on the Note 9 onwards and the Ultra models — contain a supercapacitor, not a conventional battery. It charges inductively while the pen is seated in the silo, and a full charge takes well under a minute. That charge powers the pen's Bluetooth radio for air gestures and the remote shutter.
The pen only charges when it is fully home and the retention click has engaged. If a case covers part of the silo mouth, the pen can sit a fraction proud, feel seated, and never charge. The symptom people report is "my air gestures stopped working" — the drawing and writing still work, because those are powered by the phone's digitiser rather than the pen.
Note that on the S22 Ultra and later, the pen must also be fully seated for the phone to detect removal and trigger the on-screen pen menu.
The test to run on any case
Before you commit to a case on a pen phone:
- Fit the case and eject the pen. It should pop out with a light push, no fingernail digging required.
- Reinsert it. It should go in with light pressure and click.
- Repeat five times. Any binding, any need to squeeze the case aside, means the cut is wrong.
- Leave the pen seated for a minute, then check air gestures work.
Wallet and folio cases are the usual offenders because the cover often wraps the bottom edge of the phone. Sealed waterproof cases are the other risk — some cover the silo entirely by design, which is a reasonable trade if you are taking the phone into water, but you should know before you buy.
Fold phones: the pen has to go somewhere
The Z Fold series supports an S Pen but has no silo. Samsung's answer was cases with a built-in pen slot, and that remains the practical solution — a pen that lives in your bag is a pen you never use.
If you want cards as well as the pen, combined wallet-and-pen designs exist for the same phones.
One critical warning for Fold owners: only use an S Pen designed for foldables — the Fold Edition pen or the Pro. Its tip retracts under pressure specifically so it cannot damage the flexible inner display. A standard Note or Ultra S Pen has a rigid tip and will damage a Fold's inner screen. This is not a compatibility inconvenience; it is permanent.
Browse Fold options in the Galaxy Z Fold 4 Cases collection.
Silo phones: pick a case that respects the corner
On Note and Ultra models the silo is in the bottom-left corner — which is also a corner that needs protection. A metal frame case handles this well because aluminium gives you a structural corner in a thin section, leaving room for the silo cutout.
See the Galaxy Note Series Cases collection for pen-phone specific cuts.
Frequently asked questions
My air gestures stopped working. Is the pen dead? Usually not. Seat it in the silo for a full minute, then test again. If it now works, your pen was not charging — check whether your case is fouling the silo.
Can I replace a lost S Pen? Yes. Any pen that physically fits the silo will charge in it. Buy the pen for your specific model to get the correct latency and button behaviour.
Will a Note S Pen work on an S22 Ultra? Physically yes, and it will charge. Feature parity depends on the pen generation.
Does the pen work if the supercapacitor is flat? Writing and drawing still work — those are driven by the phone's digitiser. Only the Bluetooth functions need the charge.
Can I use a Fold pen on a Note? Yes, safely. The reverse is not true — never use a rigid-tip pen on a foldable inner screen.
How do I check a case before buying? Look for the silo cutout in the product photos of the bottom edge. If it is not shown, ask via the Contact page or call 978-797-0223.
The bottom line
On a silo phone, the case's most important dimension is the bottom-left cutout. On a Fold, the case has to carry the pen because the phone will not. And on any foldable, only ever use a retracting-tip pen.