Invoicing software for agencies: what to check in 2026

Three requirements, not one

Most comparisons in this category settle the matter with a cell reading "Verifactu: yes". That cell deletes exactly the information that helps you choose, because the regulation is not one requirement but three, and they can be met separately.

The first is the invoicing record: for every invoice you issue, a record with its data has to be created at the moment of issue. The second is the hash chain: that record is computed over a fixed field order and linked to the previous one, so that altering an old invoice breaks the whole chain and shows. The third only applies if you operate in Verifactu mode and is the submission to the Spanish tax agency, with the QR code printed on the document so it can be verified.

The regulation allows two ways of complying. In Verifactu mode you transmit every record and the system is supervised from outside; in the alternative mode you transmit nothing, and in exchange the program has to offer stricter guarantees of unalterability and retention. Picking one or the other is a decision taken with the first invoice, not afterwards, so it is worth knowing which mode the program supports before you issue it.

Separating the three is not pedantry. A tool can cover the first and still be a tidy list of issued invoices. It can cover the second and guarantee that none of them is touched after issue, which is the integrity part. And it can cover the third by delegating it to another provider, which is a real case and appears below. Asking about all three separately is the only way to know what you bought.

What each program says, in its own words

The most useful way to compare four tools is to quote what each writes about itself, because that is where you see who takes on responsibility and who passes it along.

Quipu is the most formal of the four. It publishes a compliance declaration dated 29 July 2025 citing article 29.2.j of Spanish law 58/2003, the regulation and Order HAC/1177/2024, and states in writing that its system was built so that it can only ever operate exclusively as VERI*FACTU.

Contasimple carries the same date and takes the fact down to plan level, which is its distinctive contribution: the free tier is shown as Verifactu ready and the two paid plans as ready for the alternative mode as well. Holded declares it uniformly across its ladder, lists features already operating such as the event log with audit trails and automatic QR generation, and adds that it is registered as a social collaborator with the Spanish tax agency.

Factorial is the different case and the most informative one. Its own legal annex says, in Spanish, that it acts only as a facilitator of the process, providing a technological tool, and that it performs no tax reviews and no regulatory compliance checks. The filing is executed by a third party provider. That is not a fault, it is a contractual position, but it moves the liability and deserves reading before signing. The detailed comparison between the three Spanish programs is in Quipu, Holded and Contasimple side by side.

What each one costs

The billing units are not the same, so the table compares what can be compared and flags what cannot. The three Spanish programs charge per account; Factorial charges per person.

Prices checked on 8 September 2026: Quipu, Contasimple, Holded, Factorial.

Three warnings before using those figures. They are standard prices: Quipu and Holded both show considerably lower three month promotions, and budgeting on those is a scheduled mistake. Holded sells separately several modules people assume are included, such as the SII filing connector and the B2B catalogue. And in Factorial invoicing lives inside the Finance hub, whose price is on request, so the annual cost cannot be projected from their site.

What an agency needs beyond the regulation

Complying is not enough for the invoice to come out right. Three fields get used every week by a Spanish agency and are documented poorly on almost every site.

Numbering series come first. If you invoice white label for another agency, or run a separate line of business, you need independent counters that do not mix and that each keep their own consecutive count with no gaps. None of the four pricing tables explains how several series are handled at once; Holded comes closest by citing consecutive and logical numbering with no gaps or repetitions as a requirement met.

VAT regimes come second, and they are the shared gap: none of the four publishes how many it supports or which exemption grounds it covers. That is information you have to ask support for, and it is not a minor detail when your client list holds a Portuguese company, a Spanish sole trader and a reverse charge transaction. The exemption ground is the sentence printed on the invoice explaining why no VAT is charged, and getting it wrong is the sort of error that surfaces a year later, once several invoices have already gone out with the same wording on them.

IRPF withholding, the income tax a Spanish invoice may retain, comes third. Contasimple computes forms 130 and 100 and handles rental and supplier withholding; Holded includes IRPF forms from its second plan; Quipu references that family of forms as a tax feature. It does not appear on Factorial's own pages at all.

Where a content tool fits

The four programs above have something in common: none publishes to social networks, none runs an editorial calendar and none has a portal where a client approves a piece before it goes out. They are administration tools, which is why in most agencies they sit alongside the content tool rather than replacing it.

On the content side, what exists is the chain that ends in the invoice. The brief takes fifteen field types and can also be generated from a PDF the client uploads. The quote is assembled from the service catalogue, so the lines already carry a description and a price. The contract inherits those lines. And the invoice comes out of that, with its own number series, eight VAT regimes with their exemption grounds and IRPF withholding. All of it lives in agency workspaces, the ones with clients that have a fiscal identity of their own.

Of the regulation's three requirements, what is built in GoFeed is the second: every issued invoice is computed over a frozen field order and linked to the previous one. The printed QR code and the submission to the tax agency are not part of what ships, and this guide will not hint otherwise. It is the only piece of the product badged as pending, and it is stated with the same clarity on the quotes and invoices page.

What each of the four does better

Quipu, the documentary commitment. A dated formal declaration, quoting the regulation and answering explicitly which mode the system runs in, is the highest level of formality in this category, and it comes with unlimited quotes from the entry plan and full accounting with bank reconciliation and tax forecasting.

Contasimple, the front door. Its free tier is permanent and carries real invoicing rather than a trial with an expiry date, and it is the only one of the four that labels Verifactu readiness rung by rung, alternative mode included. It signs documents and quotes electronically, with the certificate type differing by plan, which is a level of detail the others leave to their support teams.

Holded, the suite. Full bookkeeping, connected banks, reconciliation rules, corporate tax, access for your accountant, automatic QR and signature generation, audit trails and the widest module catalogue. If you want to close the year inside one tool, that is the one, and the full contrast is in the Quipu comparison.

Factorial, human resources, which is its real product and a very strong one: absences, time tracking, shifts, reviews, recruiting, payroll with advisory support and legally valid electronic signature on employment documentation from the base module. The arithmetic that matters, in the end, is both subscriptions together, and the content side is on the pricing page.