Sassp

Hello, I am British, resident in UK, working from the UK, liable for tax in the UK. I have customers in the EU who pay me in euros via my wise.com account (which says on their website it is based in the UK, but my invoices state an address in Brussels as this is the address it gives you on the wise.com website). I then transfer this money to GBP into my UK bank account. I have three questions. 1. When I transfer the money into the UK GBP bank account, I write down that amount in GBP and declare that for my self-assessment. Is this correct? 2. If I leave the euros in the wise.com account and go on holiday to an EU country, and use the euros with my wise.com card there, it never comes to the UK, so how do I declare tax on this? What amount do I use? 3. Due to the wise.com account having a Brussels address, am I liable for tax in Belgium? Thanks