UK tax help in Spain

Spain is the most popular retirement and remote-work destination for Brits, and the pair of tax systems is unforgiving of drift: Spanish residence arrives at 183 days (or centre-of-interests), worldwide income becomes Spanish-taxable, foreign assets over €50k go on the Modelo 720 declaration, and the UK and Spain exchange account data automatically.

What we run from the UK side

• UK rental returns — UK first, Spanish return credits it. British nationals keep the UK personal allowance under the treaty position; the computation has to be produced in time for the Spanish deadlines, which don't match the UK's.
• UK pensions — generally taxable in Spain once you're resident (government-service pensions excepted); getting an NT code so UK PAYE stops on your pension is paperwork we do constantly. The 25% UK tax-free lump sum is not tax-free in Spain — timing it before the move is one of the most valuable single decisions a UK-to-Spain retiree makes.
• Selling up — selling your UK home after becoming Spanish-resident can create a Spanish gain even where the UK charge is small; sequencing the sale against the move matters. The UK 60-day return applies regardless.
• The departure year — split-year, P85, and a residence file you can show either tax authority (the review).

The move that deserves a timeline, not a checklist

Spain is the destination where sequencing earns the most money, because three of its rules pivot on dates you control. Residence arrives at 183 days in a calendar year — so a September move usually leaves you UK-side for the whole Spanish year, while a February move does not. The UK pension lump sum is tax-free only while the UK still has taxing rights — taken the tax year before Spanish residence, it stays tax-free; taken after, Spain taxes it as income. And the sale of a UK home is sheltered by UK private-residence relief but not by Spain once you are resident — sell before the move and the gain largely vanishes; sell after and Spain wants its share with only partial credit mechanics to soften it. Three decisions, one calendar, five figures riding on the order.

Once settled, the rhythm is stable: UK returns for UK rent (with the allowance preserved by British nationality), an NT code so UK PAYE stops on private pensions, Spanish returns via your gestor with our computations feeding the credit claims, and the Modelo 720 asset declaration handled with exact UK valuations — the fines for casual 720 filing were famously brutal even before the EU forced them down, and the declaration culture remains strict. The departure review exists for precisely this move; no destination uses it harder.