Applies to: New residents choosing Spanish mobile/broadband service and people keeping a foreign number. Provider offers change; this is a setup checklist, not a ranking or sponsored recommendation.
Pick the right tool
| Need | Useful approach | Check before relying on it |
|---|---|---|
| Data on arrival | Permitted roaming or travel eSIM | Activation clock, hotspot, compatibility and voice/SMS inclusion. |
| Keep a US number | Eligible US carrier such as Tello, or eligible Google Voice port | Actual bank-code delivery, overseas policy and service eligibility. |
| Long-term local service | Spanish prepaid/monthly +34 line | Address coverage, identity requirements and total price. |
| Remote work at home | Confirmed fibre installation plus temporary backup | Commitment, router return and a tested connection. |
Before you start
- An unlocked compatible phone; check eSIM support, available SIM slots and supported bands.
- Existing carrier account number, porting PIN/security details, renewal date and roaming terms.
- Alternative login methods for banks and important accounts; a tested authenticator or recovery codes.
- Exact home address, landlord installation permission if needed and written contract/commitment terms.
The steps
Make an arrival connection plan before travel
Decide between permitted roaming, a travel eSIM or a Spanish prepaid SIM. Install an eSIM while you still have reliable Wi-Fi, following the provider’s activation instructions; some plans start on installation, others on connection. Save the QR code/instructions securely, airport transfer details and an offline map. Check that your phone is network-unlocked and that installing a second line will not remove an eSIM you still need.
Use a travel eSIM as a bridge
Holafly is one provider to consider, alongside other travel eSIMs and your carrier. Check the exact Spain plan for data allowance/fair-use, hotspot allowance, validity, supported network and whether calls, SMS or a local number are included. Many travel eSIM products are data-focused, so do not assume they can receive Spanish bank SMS or make ordinary local calls. Set the travel line as the data line and turn off data roaming on the expensive home line unless its plan permits it.
Preserve your foreign number deliberately
You cannot port a US, UK or other foreign national number into a Spanish +34 mobile subscription as though it were a Spanish number. Keep it with a suitable home-country provider, port it to another eligible provider in that country or use an eligible internet-phone service. Do not cancel the old line first: that can prevent porting. Test inbound calls, SMS and your actual banks’ authentication before leaving, not just whether a messaging app still works.
Understand Tello, Google Voice and Google Fi
Tello’s official help describes roaming and Wi-Fi calling options for a US line; check current overseas-use terms, compatible devices, activation, emergency-address setup and SMS support. Its calling app is not automatically equivalent to native Wi-Fi calling for every incoming message. Google Voice is an internet-based phone service with eligibility and porting restrictions; some banks reject VoIP numbers for verification. Google Fi is a US mobile carrier intended primarily for US use, with international-data restrictions on extended overseas use. Neither is a substitute for a long-term Spanish mobile plan merely because the phone is a Google Pixel.
Obtain a Spanish mobile line
Compare prepaid and monthly plans, coverage at home/work/school, data, EU roaming fair-use, international calls and customer support. Bring the identification requested by the operator; passport and NIE requirements vary by product. A Spanish +34 number is useful for appointments, deliveries and local administration. With dual SIM, label the lines clearly and choose defaults for data, voice and messages. Add important contacts in international format.
Port an existing Spanish number through the new operator
Request portabilidad with matching holder identity and correct line details. Keep the old SIM active until the scheduled change and expect a short interruption. Confirm whether a bundled broadband contract, financed device or commitment remains payable. Porting a mobile line does not automatically cancel every other service. Preserve written cancellation and final-bill evidence.
Order home broadband for the exact address
Check fibre availability for the actual building/unit, not just the postcode. Ask for the installation appointment, router placement, access requirements and what is included. Confirm total monthly price after promotion, permanencia, installation clawbacks, router return, cancellation and relocation terms. Arrange temporary mobile data if you work remotely; do not promise work meetings based on an unconfirmed installation date.
Test the setup and secure it
Test calls, SMS codes, Wi-Fi calling, mobile data and video meetings before relying on the arrangement. Change the router admin/Wi-Fi passwords, install updates and consider Ethernet for work. Check signal in the room you actually use. Keep a local mobile voice route for urgent calls; an app-only number or data eSIM may not provide normal emergency calling.
Important details
A number is not a data plan
WhatsApp may continue using your previous registered number, but that does not preserve ownership of the carrier number. If the carrier recycles it, account recovery can become difficult. Update your contact number intentionally and retain secure backup access.
Avoid expensive surprises
Separate international calls from roaming: calling another country while in Spain is not the same as using a Spanish line while travelling. Ask about EU fair-use rules, premium numbers and calls to destinations outside the included zone. Prices and provider terms should be checked at purchase.
Home internet in a rental
Get installation permission when drilling or building access is needed. Ask whether an existing router belongs to the landlord or outgoing tenant and who must return it. Do not assume an advertised “Wi-Fi included” arrangement provides a separate private connection or enough capacity for remote work.
Common questions
Can I keep my US number and have a Spanish number?
Often yes with a compatible dual-SIM phone, but each line needs its own active service and settings. Verify your exact handset and providers.
Will Google Voice receive every bank code?
No guarantee. Banks and other services can reject VoIP numbers. Test each important account and set up an alternative authentication method.
Is Google Fi a permanent Spain solution?
Its international policy restricts prolonged overseas data use. Check the current terms and plan local service for a move.
See the bigger picture
Pair these practical steps with the Spain-wide essentials.
Sources & next steps
Reviewed 1 October 2026. This independent guide provides general information. Requirements, fees and office arrangements can change; the responsible authority’s current instructions control your application. Commercial service links explain products, not official rules.