Tree identification help

Any help identifying this tree in my garden would be a huge help. I’ve tried a few online apps, asked all my family and friends and even a local tree surgeon but still no luck! It’s deciduous and was in the garden when we moved in but was quite young and only 6ft tall then so I estimate it is at least 16 years old. I’ve pollarded it once, I’ve never seen any fruit or flowers or catkins so if anyone recognises it I would be very very grateful. Thank you in advance! 

Jan 🙂