Casual absences are not taken into account in calculating the 183 days. Holding a residence permit is not a pre-requisite for residence for tax purposes. The taxability of expatriates transferring to Spain is often somewhat confused as the process of applying for residence and work permits and physically moving can be so drawn out as to make it difficult to establish exactly when a person ceased to be resident in one country and took up residence in another - indeed it is possible to be resident in two countries simultaneously for tax purposes or alternatively to spend a year without being resident in any country at all.
All declarations are subject to inspection with a five year proscription period.