We did the same thing 3 or 4 years ago. We closed the front door, leaving a key in the inside lock. Despite having another key, it’s not possible to open the door whilst there is a key in the inside lock.
What a plonker.
The first time this happened I eventually managed to open the door using some technique through the letterbox – but this time I couldn’t remember how I did it. I thought of dislodging or turning the key through the letterbox but after a few pathetic attempts with a long tool I realised I was beaten and called out a locksmith.
A couple of hours later the locksmith opens the door in 10 seconds using a gadget similar to the one pictured. The gadget simply pushes down the inside handle. What a plonker – I should have been thinking handle and not key! I could have done that with something like an improvised coat hanger and I guess that is what I did the first time.
That’ll be £70 plus VAT, thank you very much. Lesson learned!!