IP ratings, water damage and the little sticker that decides your claim

A rating like IP68 is printed on the box, and most people read it as "waterproof". It is not a promise about your phone; it is a description of what a sample of that model survived under specified laboratory conditions when it was new. The gap between those two readings is where rejected warranty claims live.

Reading the two digits

The first digit describes protection against solid particles, running up to a top figure that means dust-tight. The second describes protection against water, and the scale is not a simple ladder: the higher steps describe different tests rather than strictly harder ones. Immersion tests are conducted in fresh water, at a stated depth, for a stated time, with the device stationary and at a stable temperature.

Every one of those conditions matters. Salt water is corrosive and is not what was tested. Chlorinated water is not what was tested. A jet from a tap is a pressure test rather than an immersion test, and pressure is exactly what seals are least good at. Motion through water raises local pressure far beyond the static figure. Warm water drives expansion and contraction that draws liquid past a seal that would otherwise hold.

The rating ages

Seals are adhesive and elastomer. They age with heat, with flexing, and with every drop the phone takes. A phone that has been opened for a screen replacement is sealed as well as the person who resealed it managed, and often not at all. There is no way to test the remaining ingress protection of an individual handset at home, and manufacturers are careful to say that the rating applies to a new device.

Why the warranty excludes liquid anyway

The rating is a design specification; the warranty is a contract, and essentially every manufacturer's contract excludes liquid damage. The two coexist because the rating describes the device as manufactured while the exclusion covers what happened to it afterwards, which the maker cannot observe. The instrument they use instead is the liquid contact indicator: a small sticker, usually in the SIM tray cavity or visible through a port, which is white or silver when dry and turns red or pink on contact with water. It is the first thing a service technician looks at.

The indicator is not a perfect witness. High humidity, a steamy bathroom or a long spell in monsoon air can trigger it without any immersion, and once triggered it does not reset. Inspect yours — the SIM tray comes out with the tool in the box and the cavity is visible with a light. If it is already coloured on a phone that has never been wet, knowing that before a claim is better than discovering it during one.

The first minutes after a soaking

• Power it off and leave it off. Most damage from water is electrochemical corrosion and short circuits on energised traces; an unpowered board tolerates moisture far better.
• Do not charge it. Putting current through a wet port is the single most reliable way to turn a recoverable incident into a dead phone. Modern phones refuse to charge a wet port, and the warning is not an inconvenience to bypass.
• Get the water out mechanically. Open the tray, shake the phone port-downwards, and blot. Do not use a hot dryer — heat damages seals and adhesives and drives moisture further in.
• Then wait, somewhere dry and moving, for considerably longer than feels necessary. The rice remedy is folklore: rice is a mediocre desiccant and its dust gets into ports.

If the liquid was not fresh water, rinsing briefly with fresh water before drying is the counter-intuitive right answer, because the residue is what corrodes. A phone that has been in salt water and merely dried is on a timer.

What to do about it in advance

Treat the rating as margin for accidents rather than as permission for deliberate immersion. Keep the tray closed and the gasket clean. Have the seal condition in mind when buying a used handset — a repaired phone has an unknown rating, which is one more reason to ask what has been opened, alongside the checks in the IMEI piece. And if the phone matters enough that its loss would hurt, back it up on a schedule, because the ingress rating is the one specification that protects nothing once it has been exceeded.