Choosing invoicing software might not sound like the most exciting business decision you'll make this year, but it's one of the most consequential. Get it right, and Verifactu compliance becomes a non-issue—just another background process your business handles smoothly. Get it wrong, and you're looking at frustration, wasted money, potential compliance penalties, and eventually, the pain of switching systems again.
This guide will help you make the right choice the first time. We'll walk through exactly what to look for, what questions to ask vendors, and what red flags should send you running in the other direction.
Start Here: Verify AEAT Certification (Non-Negotiable)
Let's get the most important point out of the way first: the software MUST be officially certified by AEAT for Verifactu compliance. This isn't a nice-to-have feature—it's the entire point. Using uncertified software after your compliance deadline can result in fines up to €50,000 per year.
Don't take a vendor's word for it. Don't accept "we're in the certification process" without verification. Here's exactly how to confirm:
First, check the official AEAT registry. AEAT maintains a public list of certified software solutions on their website (sede electrónica). If a vendor claims to be certified, they should appear on this list.
Second, ask for the certification number. Every certified software has a registration number. Ask the vendor for theirs and look it up.
Third, verify the certification covers what you need. Some software might be certified for one mode (VERI*FACTU or NO VERIFACTU) but not the other. Make sure the certification matches your intended use.
Red flags to watch for:
- "Verifactu-ready" or "Verifactu-compatible" claims without actual certification
- Vague timelines like "certification expected soon" without specific dates
- Vendors unable or unwilling to provide certification documentation
- Unusually low prices that seem too good to be true (certification has costs)
Know What You Need Before You Start Looking
Walking into software selection without clear requirements is like shopping for a car without knowing whether you need a compact for city driving or a truck for construction work. You'll waste time looking at wrong options and might end up with something that doesn't fit.
Before contacting any vendors, sit down and answer these questions:
How many invoices do you issue monthly? A freelancer sending 10 invoices a month has very different needs from a company issuing 1,000. Volume affects pricing tiers, performance requirements, and which features matter.
How many people need access? If it's just you, a simple solution works. If you have a sales team, an accounting department, and a customer service team who all touch invoices, you need multi-user capabilities with proper role management.
What systems must it integrate with? Your invoicing software will need to talk to other systems. At minimum, that's probably your accounting software. It might also include your CRM, e-commerce platform, inventory management, or ERP. List everything.
Do you prefer cloud or on-premise? Cloud solutions are easier to maintain and update automatically. On-premise gives you more control and might be required for certain security or compliance needs. Most small businesses do fine with cloud.
Which mode do you want: VERI*FACTU or NO VERIFACTU? If you're comfortable with real-time reporting to AEAT and want the simplest compliance path, choose VERI*FACTU. If you have privacy concerns or prefer local storage with on-demand reporting, look for software supporting NO VERIFACTU mode.
What's your realistic budget? Don't just think about monthly fees. Consider implementation costs, training time, integration development, and the productivity loss during transition. Get a realistic total picture.
Evaluating Technical Capabilities
All AEAT-certified software meets minimum technical requirements—that's what certification means. But there's a difference between meeting minimum requirements and implementing them well. Here's what to evaluate:
Hash chain implementation and verification: Every invoice gets linked to the previous one through cryptographic hashing. Ask to see how you can verify your hash chain is intact. Good software provides easy-to-understand integrity reports. Poor implementations make verification confusing or manual.
Digital certificate management: You'll need to configure your digital certificate for signing invoices. How easy is this? What happens when your certificate expires? Does the software warn you in advance? Some solutions handle certificates elegantly; others make it painful.
QR code quality and placement: Every invoice needs a scannable QR code. Test it yourself—scan QR codes from sample invoices with your phone. Do they work? Are they positioned well? Can you customize placement if needed?
AEAT connectivity (for VERI*FACTU): If you're using VERI*FACTU mode, your software communicates with AEAT's systems. Ask about uptime, what happens during AEAT outages, and how the software handles transmission failures. Look for automatic retry mechanisms and clear error reporting.
Data export and portability: You should be able to export your invoice data in standard formats. This matters for audits, for integration with other tools, and critically, for leaving this vendor if you ever need to. Avoid solutions that lock your data in proprietary formats.
Audit trail access: The software maintains detailed logs of everything—invoice creation, modifications, exports, user actions. How easy is it to access and understand these logs? You'll need them during tax audits.
Don't Overlook Support and Vendor Stability
Here's something many buyers underestimate: the quality of vendor support and the stability of the company behind the software. Features look great in demos, but they don't help you at 9 PM when something breaks and you have invoices to send.
Test support before buying. During your trial period, contact support with questions. How quickly do they respond? Are responses helpful or generic? Can you reach a human, or are you stuck with chatbots? Do they offer support in Spanish (or whatever language your team needs)?
Check support hours. If your business operates unusual hours, make sure support is available when you might need it. 9-to-5 support doesn't help if you do most of your invoicing in the evening.
Research the vendor. How long have they been in business? Are they profitable and stable, or a startup burning through funding? What's their track record with regulatory compliance in other areas? Read reviews from other Spanish businesses. Check LinkedIn for employee stability.
Ask about their update commitment. Regulations change. AEAT will modify requirements over time. Does the vendor have a track record of keeping up with regulatory changes? How do they handle updates—automatically, or requiring manual action from you?
Calculating the True Cost
The subscription price you see on a website is just one part of the total cost. To compare options fairly, you need to calculate the full picture:
Software subscription: The base monthly or annual fee. Watch for per-user pricing that scales up with your team, volume-based tiers, and features locked behind higher plans.
Implementation costs: Some vendors charge for initial setup, configuration, and data migration. Others include this in the subscription. Get quotes for your specific situation.
Integration development: If you need custom integrations with your existing systems, who builds them? What does it cost? Even if the vendor offers pre-built integrations, you might need customization.
Training: Factor in the time your team will spend learning the new system. Some solutions are intuitive; others have steep learning curves. Also consider formal training costs if the vendor offers paid training programs.
Productivity loss during transition: There's always a dip when switching systems. Your team will be slower initially. Factor this into your calculations, especially if you're implementing during busy periods.
Add all these up over a 3-year period. That's your real cost of ownership, and it's what you should compare between vendors.
Test Before You Commit
This might be the most important advice in this entire guide: never, ever commit to invoicing software without testing it first. Demos are marketing. Trials are reality.
Most reputable vendors offer free trial periods. Use this time seriously—don't just click around for 10 minutes. Put the software through its paces:
Create invoices matching your real scenarios. Not just simple invoices, but complex ones with multiple line items, discounts, different VAT rates—whatever you typically deal with.
Test the QR verification. Generate invoices and scan the QR codes. Verify they work correctly through AEAT's system.
Test your integrations. If you need the software to connect with other systems, test those connections during the trial. Don't assume they'll work—verify.
Involve actual users. Don't test alone. Have the people who will use the software daily try it out. Their feedback matters more than yours.
Test support. Contact support with real questions during the trial. Judge their response quality and speed.
Push the limits. What happens when you create many invoices quickly? How does the software handle errors? Try to break it—better now than after you've committed.
Making the Final Decision
After evaluating your options, narrow down to 2-3 finalists and create a simple comparison matrix. Score each option on:
- Certification status (pass/fail—only certified options remain)
- Feature fit for your needs (1-5 scale)
- Ease of use based on trial experience (1-5 scale)
- Integration capabilities (1-5 scale)
- Support quality based on trial experience (1-5 scale)
- Vendor stability (1-5 scale)
- Total cost of ownership (actual figures)
Weight these factors based on what matters most to your business. For most companies, certification is non-negotiable, support quality is crucial, and total cost matters more than the lowest subscription price.
Trust your gut too. If something feels off about a vendor—pushy sales tactics, vague answers, reluctance to provide references—that's valuable information.
Remember: you're choosing a tool you'll use every day for years. A few extra hours of evaluation now will pay off many times over.