If you only use your Spanish bank account to pay bills and you can pay said bills online using a debit card there are a couple of alternatives to not having a Spanish bank account and they are free to use. The downside is that you have pay them separately every month as there is no direct debit service available.
One is the revelut card that you top up in sterling and can pay out in any currency, and can be managed on line or via a smart phone.
https://www.revolut.com/es/?lang=en&lang=enAnother is either Transferwise or Transferwise Borderless Account.
https://transferwise.com/es/https://transferwise.com/borderlessThose of us who are living/used to live in UK are used to completely free banking whilst the rest of Europe are used to paying some banking fees, so it comes as somewhat of a shock to be paying circa 100€ per annum for banking services in Spain.
We who are resident in Spain can still enjoy totally free banking, we are with Sabadell who are, for us, excellent. We deposit a minimum of 700€ per month and everything is free.