If you are searching for how much it costs to build a custom app in Spain in 2026, the short answer is: it depends on scope, and scope is where most quotes quietly fail.
The useful answer is an orienting band. This piece collects the ranges you commonly see in the Spanish market for websites, ecommerce, and custom software. They are market ranges, not anyone’s rate card: every serious project is priced after scope is defined.
It also explains what moves those bands, why a locked budget after definition is safer than an open time-and-materials meter, and which red flags to watch when a quote looks too cheap. At the end it points to the approximate calculator and a free 15-minute call, in case you want to move from reading to your own case.
Read it as a buyer’s map, not a rate card. The goal is to walk into vendor calls already knowing which band you are negotiating inside, and which promises cannot fit that band.
Why Spain asks “price” before “stack”
In the Spanish market, the first question is almost never “React or Flutter?” It is “how much until something usable ships?” That makes sense: many founders and ops teams fund the first slice from cashflow, not a Series A.
That changes how you should read a quote. A vendor that only sells an hourly rate with no ceiling is selling uncertainty. A studio that locks price after defining scope is selling a ceiling. That ceiling is what you can compare across offers.
SEIRO is headquartered in Spain, fully remote, with clients worldwide. Client delivery has existed since 2023; the SEIRO brand was established in 2025. The method does not change with geography: we agree what to build, and what to leave out, before any code.
Price bands in Spain (2026)
These bands are orienting and describe the Spanish market in general: ranges you often see in quotes from studios and agencies. They are not SEIRO prices and not a closed catalog: every project is priced after scope is defined. Use them to orient yourself before you collect three quotes, and to discard quotes that do not match your stage.
- Professional website: in the market, usually from around €1,500. A modern, maintainable site, not a generic theme with no ownership story. Fits when you need owned presence, not a multi-role product.
- Ecommerce (Shopify / WooCommerce) or migration: usually from around €2,000. A store you can operate with a real checkout. Large catalogs, shipping rules, ERPs, or custom checkout move the band up quickly.
- Custom software, automations, and AI systems: a well-bounded first slice usually starts from around €5,000. MVPs, digital products, internal tools, and multi-role platforms.
- Typical market range for custom work: roughly €5,000–€50,000+. Above that you are usually in multi-team delivery, deep integrations, or multi-phase product work already validated.
How to read these bands without kidding yourself
A band is not a promise that “your app costs X.” It is a reference. If your brief is “site with booking and gallery,” you live near the entry tier. If it is “three roles, payments, admin, ERP sync,” you are in custom software, and €5,000 is a floor, not the typical.
Founders miss in two directions. Some assume “app” always means €80,000 and freeze. Others assume a landing-page quote will build a marketplace. Both mistakes cost months.
The clean way to use these bands: write the core action, mark what is out of scope, and place the result in a range before you compare vendors. If three studios quote different worlds, the brief still allows three different products.
What actually moves cost (more than the stack)
Stack choice matters less than founders think. Next.js versus another framework rarely explains a €20,000 jump. These do:
- Roles and flows. One user completes one action. Three roles (customer, admin, partner) multiply screens, permissions, and edge cases.
- Integrations. ERP, payments, CRM, messaging, accounting: each external system adds contracts, failure modes, and maintenance.
- Data and compliance. Personal data, regulated sectors, or audit needs raise design, logging, and legal review.
- Launch quality. A production-usable MVP is not a weekend prototype. Tests, observability, and handover are part of the price.
- Scope ambiguity. “An app like Uber” is not a brief. It is an open invoice. Without definition, the real cost appears mid-project.
A practical rule: every extra role and every “must-have” integration should explain why the core action fails without it. If it cannot, it is Should or Could, and belongs after validation.
How AI changes the cost (and what it doesn’t)
Engineers who use AI every day build faster, so the build share of a budget shrinks. Tests, review and decisions don’t shrink the same way. A quote that is cheap because it skipped them is not cheaper: it costs more later.
At SEIRO we try every new tool on our own work first and bring to your project only what works and fits. That’s why we can show you where the savings come from, and where they don’t. What we tested, adopted and dropped is in our Edge Log.
The lever that lowers price most: cutting scope
At SEIRO we agree what to build, and what to leave out, before any code. The goal is not a longer kickoff. It is finding the few features that deliver most of the value and parking the rest.
In practice, that conversation usually moves several things founders planned to build out of the first slice. Those ideas are not bad; they are version-two ideas. They belong after real users, and when it applies real money, prove the core.
That cut is usually the biggest saving in a project. It is not a cosmetic discount on the same scope. It is not building what you do not need yet, then budgeting only for what remains.
If you want to start there, a free 15-minute call is enough to go through your list and see what stays out. If the idea does not hold, better to learn that now than in month three of code.
Fixed budget vs time-and-materials
Two models still dominate quotes in Spain. Neither is morally superior; they change who carries uncertainty.
- Time and materials (T&M). You pay for hours. Useful while the problem is still being discovered. The risk sits with you: every change of mind extends the invoice.
- Fixed budget after definition. You lock scope, milestones, and price. Changes go through an explicit scope change. Ambiguity is paid for up front in definition, not in sprint eight.
To validate a product, most founders need to know how much they will spend. T&M is not “bad”: a clear ceiling changes the conversation from “how many hours are left?” to “does this validate the hypothesis?”
If a vendor only quotes hourly with no cap and no milestones, ask what happens when scope grows. If the answer is “we keep billing,” you already know the risk model. Also ask who decides what counts as a “change” versus a “brief bug.” If nobody wrote it down, the invoice will decide.
One important nuance: fixed budget does not mean infinite scope at a fixed price. It means agreed scope at a fixed price. That is why definition is not a luxury. It is the mechanism that makes the lock honest.
Red flags in cheap quotes
A low price is not always a trap. Sometimes it is an honest, minimal scope. These signals deserve a pause:
- The quote arrives with no questions about users, success metric, or what is out of scope.
- They promise a “full app” at a landing-page price with a marketing timeline.
- There is no definition phase, no exclusions list, and no acceptance criteria.
- Code ownership, repository access, or hosting are left vague.
- “Senior” names supervise while day-to-day work is junior with no access to the decision-maker.
- They compare only hourly rate, not cost-to-a-usable production outcome.
An honest €8,000 quote with surgical scope usually beats a €4,000 quote that hides three months of change orders. The number on page one matters less than the number on launch day.
Also beware the opposite extreme: padded “just in case” quotes with no exclusions map. Padding without definition is not professionalism; it is billed fear.
How to bound your number before you request quotes
Do this in one afternoon, before you send RFPs. It will save you rounds of calls that compare different products wearing the same title.
- Write the core action in one sentence: “A user [verbs] a [noun] to [outcome].”
- List everything you have imagined. Be exhaustive. Get the inventory out of your head.
- Mark Must / Should / Could / Won’t. If the core action works without it, it is not Must.
- Cut expensive Musts unless they are impossible to substitute (manual process, third-party tool, thinner version).
- Pick a validation metric: payment or repeat use. Your scope must include a way to measure it.
- Place the result in a band (with the calculator or the bands above) before you compare vendors.
What a locked-budget engagement feels like
After definition, the build should not feel like a fog of hours. It usually looks more like this: clear milestones, frequent demos, and an explicit list of what is out of scope. When something new appears, and something always does, it is discussed as a scope change with schedule or price impact, not as “we will slip it in.”
That discipline is what makes studio comparisons honest. You are not buying an “agile” slogan. You are buying a ceiling and a done criterion. When those are missing, the opening price stops being useful information.
If the first meeting only talks about stack and never about users, success metric, or exclusions, you are buying implementation without product. The real cost of that almost never shows up on the first invoice.
From a band to the next step
If you are still orienting, the calculator gives an approximate estimate from product type and complexity. It is not a quote or SEIRO pricing, but it is a base for a more grounded conversation.
If you want a reliable number, the path is to define scope before you ask for price: core action, exclusions, and validation metric. Any serious studio should help you with that before quoting.
If you want an honest read on whether the idea holds, book a free 15-minute call. No sales pitch. If there is no case, we will say so.
See the Spain custom software page (how we work and cases) →
Where SEIRO sits on this map
SEIRO is a team of software engineers in Spain. We test new technology on our own work first, and bring clients only what works. We build custom software, automations, and AI systems, and we agree what to build, and what to leave out, before any code.
If you are between “I think I need an app” and “I need a number I can trust,” start with the calculator or a free 15-minute call. The rest of the site (work, capabilities, the Edge Log) exists so you can verify method and proof before you decide.
Frequently asked questions
Can AI make my project much cheaper?
Faster, yes. Cheaper, often. But only if tests and review stay in the budget. We show you where the savings come from.
How much does a custom app cost in Spain in 2026?
As a guide to the Spanish market: a professional website usually starts from around €1,500, ecommerce from around €2,000, and a first slice of custom software, automation, or an AI system from around €5,000, with a typical band of €5,000–€50,000+ depending on scope. These are market ranges, not SEIRO prices: the real number depends on the scope you define.
Why do quotes for “the same app” differ so much?
Because it is almost never the same app. Roles, integrations, compliance, and launch quality change the real work. A vague brief produces incomparable quotes.
How do I get a reliable number before building?
Define scope first: the core action in one sentence, what is out, and how you will measure whether it works. With that, quotes become comparable; without it, any number is a guess. Be wary of anyone who quotes a fixed price without asking those questions.
Fixed budget or time-and-materials?
T&M fits when you are still exploring. To validate a product with a spend ceiling, a fixed budget after definition is usually safer: changes become explicit scope changes, not silent hours.
How do I get a quick range?
Use the cost calculator on seiro.io for an approximate estimate (it is not a SEIRO quote), or book a free 15-minute call to talk through your case.
Do these prices include ongoing maintenance?
The bands in this article cover the build / launch slice. Ongoing maintenance is agreed separately for the system delivered. Always ask what sits inside the locked price and what is a later phase.
Get a range for your project.
Send three lines about it, or book a 15-minute call. Either way you get a range, at no cost.