Hey there,
As you took out your contact in July, it means you still have free roaming in the EU as part of your deal.
This means you can go there and use your phone as you would here in the UK.
There is a caveat, as free roaming is meant to be for short visits rather than permanent living abroad, you may be contacted after a few months to alert you to the fact they've picked up on this and plan to start applying a surcharge to your usage.
This has always been part of the terms and conditions yet I've never seen anyone come here to say it's actually happened to them. So you may be lucky. It's just something to be aware of.
Should this happen then I would ensure your device is unlocked so you can buy and use a local Belgian sim for the remainder of your year in Belgium.
