Below are the ones that come up repeatedly and are entirely avoidable with the right preparation.

You cannot enter Spain as a tourist and then apply for a long-stay visa from within the country. The long-stay visa must be obtained from the Spanish Consulate in the UK before you travel. People who arrive planning to sort it out on the ground find themselves in a legal grey area that is difficult and expensive to resolve.

Most people assume 2-3 weeks is enough to gather everything needed for a visa application. In reality, between obtaining the ACRO criminal record certificate, getting it apostilled, arranging sworn translations, securing the right health insurance, and booking a consulate appointment, 6-8 weeks is a minimum. Starting too late forces rushed decisions and increases the risk of errors.

The Non-Lucrative Visa and the Digital Nomad Visa are regularly confused, and the consequences of applying for the wrong one are months of wasted time and rejected applications. Someone who intends to work remotely and applies for the NLV will face problems the moment they start working. 

The year you move is the most complex tax year you will have - you are a UK tax resident for part of it and a Spanish tax resident for part of it, with potential obligations in both countries. Many people assume it sorts itself out automatically. It does not. Failing to notify HMRC via P85, failing to file a Spanish tax return for the transition year, or failing to apply for the Beckham Law within the six-month window are all mistakes that have real financial consequences.

The Padron certificate is required for your NIE appointment, your TIE application, opening a bank account, registering with a doctor, and almost every other administrative process you will go through in Spain. Some people delay registering on the Padron because they are not sure where they will settle long-term. Register as soon as you have a fixed address, even if it is temporary rental accommodation.

In major expat areas and cities, getting by in English is possible. In most of Spain, a functional level of Spanish is essential for healthcare appointments, government offices, dealing with landlords, and daily life. People who arrive with no Spanish and no plan to learn it consistently report frustration with bureaucracy, social isolation, and in daily chores.

For Non-Lucrative Visa holders especially, private health insurance is a visa condition. Switching to a policy that does not meet Spanish requirements can jeopardise visa renewal. Keep insurance documentation current at all times and ensure any new policy meets the same standards as the original one required for the visa application.