Why Your Highchair Harness Keeps Coming Loose and How to Fix It

Quick answer

A harness that keeps coming loose is almost always a threading or tension problem, not a worn-out strap. Re-thread the shoulder straps through the correct slots, pull the adjuster tail to set tension, then check the buckle clicks and stays clicked under a firm tug. If the buckle still releases or the strap still slides after that, stop using the seat until you have inspected the buckle and webbing properly.

Check the threading before you blame the buckle

Most loose harnesses are threaded incorrectly after cleaning or a growth-spurt adjustment. The shoulder straps should pass through the slot that sits level with, or just below, your child's shoulders, and the webbing must lie flat with no twists. A twisted strap cannot be tensioned evenly, so one side creeps loose while the other stays put.

Loosen the harness fully, unclip the shoulder pads, and follow each strap from the buckle back to the splitter or adjuster. Re-thread one side at a time so you can see exactly where the webbing sits. When both sides are flat and correctly slotted, tighten the adjuster tail and test again.

• Shoulder slots level with or just below the shoulders, never above them
• Webbing flat, no twists, no folds trapped under the pad
• Both shoulder straps seated in the same slot height

Set tension so it holds without pinching

Tension is the part parents get wrong in both directions. A harness that is too loose lets a child lean forward or slide a shoulder free; one that is too tight is uncomfortable and encourages a child to push against the buckle. The practical test is the flat-of-two-fingers gap between the strap and your child's collarbone.

Tighten using the adjuster strap at the front or side of the seat rather than pulling the shoulder straps themselves. Pulling the shoulders stretches the webbing and leaves slack in the adjuster, which is what creeps back out during a meal. If your seat uses a five-point harness, tighten the lap portion first, then the shoulders.

• Two fingers flat under the shoulder strap is the working target
• Tighten via the adjuster tail, not by hauling on the shoulder straps
• Re-check tension after your child is seated, not before

When the buckle is the real culprit

If the buckle clicks but releases under a firm tug, or only one side latches, stop using the harness. Food, puree, and dried milk get into the buckle mechanism and stop the internal clips engaging fully. A buckle that has been through the dishwasher or soaked in hot water can also lose the lubricity that lets it latch cleanly.

Clean the buckle with a damp cloth and mild soap, then work the release button repeatedly while it is open. Do not oil it, and do not force it shut. If it still will not latch securely on both sides, treat the harness as failed and contact the manufacturer for a replacement part rather than continuing to use the seat.

• Buckle must click on both sides and stay clicked under a firm tug
• Wipe food out of the buckle after every messy meal
• Never oil a buckle or force it closed

Cleaning without wrecking the webbing

Harness webbing loses its grip when it is washed with fabric softener, dried in a tumble dryer, or scrubbed with bleach. Softener coats the fibres and makes the strap slide through the adjuster, which is exactly the symptom you are trying to fix. Wipe the straps with a damp cloth and mild soap, then air dry them flat and away from direct heat.

If your seat has a removable cover, take it off to clean it rather than soaking the whole harness. Check the webbing for fraying, stiffness, or shiny flattened patches while it is off. Any of those signs means the strap needs replacing, not re-threading.

• No fabric softener, no bleach, no tumble drying
• Air dry flat and away from radiators
• Replace frayed, stiff, or shiny webbing

Diagnose the looseness

• Symptom: one shoulder strap slides loose: The strap is usually twisted or threaded through mismatched slots, so tension cannot hold on that side. Re-thread both shoulders to the same slot height, flat and untwisted, then retest.
• Symptom: harness feels tight but your child still leans forward: The lap portion is too loose, so the shoulders have room to move even when the upper straps feel snug. Tighten the lap straps first, then the shoulders, and re-check the two-finger gap.
• Symptom: buckle clicks but releases under a firm tug: Food debris or a soaked buckle mechanism is stopping the internal clips from engaging fully. Clean and exercise the buckle; if it still releases, stop using the seat and get a replacement part.

Product facts

• iCandy MiChair Highchair - Black: The iCandy MiChair Highchair is a multifunctional seat that transitions from a highchair to a toddler chair and is compatible with the optional iCandy Newborn Pod, suitable from birth up to approximately six years old. Because the seat is used across several years and configurations, the harness gets re-threaded and re-tensioned repeatedly, which is when most loosening problems start.

If re-threading, retensioning, and a proper buckle clean do not hold, stop using the harness and contact the manufacturer for a replacement part. A harness that will not stay tight is a safety failure, not a maintenance annoyance.