If you are the spouse of a citizen of the Republic of Ireland, which falls under the European Union, you will have no issues requesting permanent residency in Spain, however it does not matter much that your spouse originates from a country within the European Union and there are some rules and requirements to adhere. The process you should follow is to first apply for a NIE number at the Policia Nacional, this is the tax identification number for foreigners in Spain. The NIE does not expire, and will allow you to rent or buy a property - it does not grant you a residence permit per se.
Applying for your NIE can be tedious and frustrating, you'll need to be able to speak basic Spanish and be prepared for long queues. I recommend you make an appointment via the website of the Spanish government, to be precise the "Administraciones PĂşblicas" department, and pick a Policia Nacional station in a lesser touristic town or city, such as Alcoy. This can save you an entire day of waiting in line. The link to make the appointment is:
Proceso automático para la solicitud de cita previa
Following your NIE application and once you have an address, you need to register in the "PadrĂłn Municipal", you do this by going to the town hall ("ayuntamiento") of your municipality where you will present your rental contract, deed of a purchased property in your name or in case of a property in the name of your spouse a statement granting you permission to use said address as your place of residence, after which the town hall will register you at said address. This process is called "empadronar" and generally only takes a couple of minutes.
When you are in possession of both the NIE and a "volante de empadronamiento" (proof of registration in the municipality) you can now request a TIE card. The TIE card is the official identity document for foreigners in Spain and features your photo, personal details and address of residence, and is essentially your residence permit - it's simply an ID card that also mentions your address. The TIE card needs to be renewed when it expires, I believe the period of validity is 5 years.
To be granted a TIE card (and as such, a residence permit), you will need to be able to provide one of the following:
- proof of employment in the form of a work contract (or pre-contract if you have not started working), OR;
- proof of private health insurance, fully comprehensive and paid 1 year upfront, AND proof of funds in a Spanish bank account in your name - minimum of €7000 for individuals, or €10.000 for married couples. Proof of funds need to be stamped and certified as authentic by your Spanish bank - screenshots of internet banking will NOT suffice, neither will accounts at online banks such as N26 or Revolut. In case you own the property of your residence in Spain and have paid off a fair amount of the mortgage (there are no set rules for this), this can also suffice as proof of funds.
If you're self-employed in Spain, don't get me started - lots of forms and basically means setting the difficulty level to "Extreme".
The backlog for TIE applications in most municipalities is huge, so it's important you take care of all paperwork directly following up on your NIE and empadronamiento.
Your spouse will have a breeze in comparison - she just needs to have a NIE number and empadronamiento. Officially it is required to apply for the TIE if your stay in Spain is longer than 3 months, but generally most people don't even bother and never go past simply registering at the town hall.
Hope this helps.