Unlock seatbelt seat belt locked

First off, are you able to move the seat forward, backward, or upward to free up the tension on the seat belt lock so you can again pull out slack? If not, are you able to raise or remove the headrest to create slack in the seatbelt and release the lock? Without a photo of the situation it's difficult to understand how you managed to get a seatbelt stuck around a headrest....

Edward sounds like a stuck counter weight in belt retractor, links below should help. PRESS THE HELPFUL BUTTON

How to Release Locked Seat Belt

HELP Seat belt Locked up Ford F150 Forum Community of Ford Truck Fans

How to Repair Ford Seat Belt eHow

Airbag Systems How to Repair Sealtbelt Pre Tensioner

check the mechanism where belt coils it should only lock when suddenly pulled out- compare with working belt

9 times out of ten you half to replac them even if was a minor fender bender. The seat belt reel has a component the breaks and locks under a certain amount of load.

The safety belts are sensible to release speed (u have to release it kinda smooth).Also they are sensibile to car inclination (lean) may not release whel when rise/fall position.If locked,u may have to shake a little the belt so the locking spring/balls to unlock.Eventualy ,when driving it can release by itself.One thing is for shure:no sudden moves:it locks again (as in the impact scenario)Cheers

You can't unlock the seatbelts. They have an explosive charge built in that goes off like an airbag, locking up the belts on impact. You will have to replace all your locked up seatbelts.

eremove seatbelt cover, locate the safety lock lead or metal at the bottom of seatbelt assembly, remove the plastic roto that locks , push slightly teh belt and if u think lock is release, slowly pull the belt.

I can't be of much help, except to indicate what Honda says about the seats, and to give you a URL to look at:
Using a Seat Belt Locking Clip
Always use a seat belt locking clip when you secure a child seat to your car with a lap/shoulder belt. This helps prevent the seat from shifting position or overturning. A locking clip is usually included with the child seat. If you need a clip, contact the seat's manufacturer or a store that sells child restraints.
The URL will take you to a more complete reference to your car manual regarding child restraints.
https://techinfo.honda.com/rjanisis/pubs/om/AC9595/AC9595O00020A.pdf
Hope this helps you.

rear seat belts lock if you pull them out all the way and put them ALR mode. Automatic Locking Restraint. It will ratchet as the belt is rewound. This is for holding a child seat in place.

Is this your issue?