Construction management · sole traders with a crew, micro firms and small builders
OBRASET imports the BC3 file your architect sends, tells you whether a refurbishment qualifies for the 10 % VAT rate before you sign, issues cumulative certificates with their retention money, and shows you every morning which job is making money and which is not. Invoices carry the Verifactu seal because FACTUSET issues them.
Materials ceiling
40 %
Above it, the whole refurbishment is taxed at 21 %. We watch it live.
Cost columns
4
Sale, planned cost, committed and incurred. Per chapter.
Subcontracting chain
3
Tiers at most. The register warns you before you cross the line.
Flat-rate withholding
1 %
Applied on its own to invoices you receive, and carried into forms 111 and 190.
The date that will not move
Verifactu requires every invoice to be born as a chained, tamper-proof record with its own hash and a QR code the Spanish tax agency can verify. A spreadsheet will not do, nor a Word template, nor a program that numbers invoices and leaves them loose in a folder.
In OBRASET that part is not your problem: the invoice is issued by FACTUSET, our own invoicing engine, with its series, its chaining and its filing with the tax agency. You get on with the job.
1 · 1 · 2027
Companies — corporate income tax payers
1 · 7 · 2027
Self-employed traders and everyone else
Royal Decree-Law 15/2025 · RD 1007/2023 · Order HAC/1177/2024
What actually happens in a small builder's office
It is not untidiness: it is that construction work does not fit into ordinary invoicing software. An estimate is not an invoice with more lines, an interim certificate is not a delivery note, and the cost of a job does not show up on a bank statement.
01
A 400-item BC3 file arrives and you retype it. One measurement changes and you recalculate overheads, general expenses and industrial profit all over again. Which version the client actually signed is anyone's guess.
02
Measurement for the period, measurement to date, 5 % retention money and a pro-forma for the supervising architect to approve. And then the usual doubt: does this trigger VAT yet or not?
03
By the time supplier invoices, delivery notes and crew hours finally reconcile, the job has been closed for two months. If you got the structural chapter wrong, there is nothing left to fix.
OBRASET puts the job at the centre: estimate, certificates, purchasing, site sheets and documents are tabs of the same record. Nothing lives on its own.
The modules, one by one
Chapter, work item, measurements with their units × length × width × height, and the breakdown with its labour, plant, materials and percentages. The closing percentages — indirect costs, general expenses, industrial profit and tender discount — are set per estimate.
Job record · the estimate tree
OBRASET reads FIEBDC-3: chapters, items, breakdowns, long texts and measurements with their lines and subtotals. The first thing it does is read the declared character set and the decimal places per magnitude, because that is what decides whether totals match Presto or Arquímedes instead of leaving a stray cent in every chapter.
If it does not understand a record — specifications, parametric items, attachments — it skips it and logs it, but never aborts the import. When it finishes it shows you what came in and what did not: mismatches between the declared price and the one recalculated from the breakdown, orphan concepts and formula-driven measurements.
Why the ~K record matters
The decimal places per magnitude declared in the file are honoured in every recalculation. That is the difference between an estimate that agrees with the designer's and one that argues with it over rounding.
BC3 (FIEBDC-3) import diagnostic
The reduced rate for home refurbishment has three requirements that are met all together or not at all, and the third is the one that slips: the materials you supply must not exceed 40 % of the taxable base. OBRASET computes that percentage live from the unit-rate breakdowns — it is never typed in — and warns from 35 %, while you can still move an item.
Go over 40 % and the entire invoice is taxed at 21 %. It cannot be split in two. Better to know now than in a tax audit three years later.
The editor warns from 35 %
Article 91.Uno.2.10º of the Spanish VAT Act: an individual customer using the home privately or a residents' association, a dwelling completed at least two years ago, and materials below 40 %.
VAT assistant · the materials share, live
A valuation by chapters showing what was executed in the period and what has accrued to date, and a status flow that matches reality: draft, pro-forma sent to the supervising architect, approved, invoiced. The pro-forma is a PDF with no tax effect, so the architect can sign off before an invoice exists.
Certificates · cumulative valuation
Four columns per chapter, which are the four questions that matter: what you sold, what you planned it would cost, what you have committed in purchase orders and what it has actually cost. With the variance in euros and as a percentage, colour-coded, and the result of the job in real time.
Incurred cost is not an estimate: it comes from approved supplier invoices, allocated expenses and site-sheet hours valued at the LABORSET hourly cost. If a chapter is drifting, you see it while it can still be corrected.
The worst variance, at the top
A job never warns you by itself. What warns you is the chapter already 18 % over when half of it is still to be built.
Cost control per chapter
The month's delivery notes are grouped into the supplier's monthly invoice and matched on quantity and price. Whatever does not add up stays flagged in amber, not buried inside the total.
Purchasing · delivery-note matching and comparison
Site sheets arrive from the job and hours are valued at the cost per hour LABORSET publishes for each grade: gross from the wage tables, employer social security, the construction industry training levy, accrued severance and bonus payments, divided by effective hours. That figure is what feeds the incurred cost of the job.
On this screen no hours are typed at all: time recording, payroll, contracts and social security belong to LABORSET, which already handles them through CEGID. OBRASET only tells it which job each hour went to.
Job documents with a traffic light
Site opening notice, health and safety plan, permit and waste management, each with its own status. Whatever expires, warns.
Site sheets from the job + documents
OBRASET neither numbers nor signs invoices: it asks FACTUSET for them, and FACTUSET adds the series, the Verifactu chaining, the tax agency's QR code and the filing. In the table you see the number with its hash underneath, the VAT treatment in plain language — 10 % refurbishment, 10 % renovation, 21 %, reverse charge — and the payment status.
Invoicing, Verifactu, FACe and collections
One column per document and a coloured dot in each cell: the construction-sector register (REA) with its three-year expiry, the tax agency certificate under article 43.1.f, social security clearance, the monthly payroll return and the public liability policy with its receipt. Green, amber or red, no interpretation needed.
The rule is deliberately hard: a red document blocks payments to that subcontractor. Only an administrator can release them, and the reason is recorded. Because an expired tax certificate is not paperwork: it is secondary liability for the tax debts of the firm you hired.
Act 32/2006 and RD 1109/2007
Contracting a subcontractor without a valid REA entry is a very serious infringement. OBRASET will not let you get there without having warned you.
Document traffic light and subcontracting register
A read-only user with access to all your companies, the period's tax returns — 303, 111, 115, 130, 349 — and the accounting export in the format they already use: a SUENLACE.DAT file for a3ASESOR or Sage Despachos, with the sector-specific retention-money accounts exactly where they belong.
Accountant channel · tax returns and accounting export
The owner's app
Estimating, certifying or invoicing from a phone on site is not a good idea, and we are not going to pretend otherwise. The OBRASET app is for looking and deciding: your portfolio of jobs with their traffic lights, cost against estimate, certified but not invoiced, awaiting payment, and a short list of what needs your attention today.
Portfolio · March
Your jobs
Payments blocked · Ferralles Vallès: tax certificate expired
How it fits with the rest
OBRASET does not reinvent invoicing or payroll: it leans on two engines already in production in real firms and practices. Fewer places to enter the same data, fewer places to get it wrong.
The job
Jobs, estimates with BC3, certificates, purchasing, cost control, subcontractors and compliance. This is where you work.
The invoice
Series, Verifactu with chained hashes and QR codes, filing with the tax agency, signed Facturae and FACe. Invoices live here, which is where your accountant comes in.
The workforce
Time recording, contracts, payroll and social security through CEGID. This is where the hourly cost that values every site sheet comes from.
Plans
OBRASET is construction management software: you pick the plan by what you need switched on, not by how many invoices you issue. Advisory work — tax, employment, compliance, contract review — is quoted separately and to measure, because a three-person builder and a thirty-person one do not need the same thing.
Sole trader or a small crew. The spreadsheet's replacement.
€24/ month · VAT not included
The reference plan
Contracted work that gets certified and has to be controlled from the inside.
€49/ month · VAT not included
Builders who subcontract and work with several people inside.
€89/ month · VAT not included
Behind OBRASET there is a firm of lawyers and tax advisers. If you would rather we also handled tax, employment and site compliance, we put together an advisory fee with the software included, priced on your turnover of work and your headcount. One point of contact for the job, the invoice and the payroll.
No lock-in. Your estimates, certificates and documents are yours and you can take them with you whenever you like; invoices stay in custody for as long as the law requires.
Questions from site, not from a brochure
For companies, from 1 January 2027; for self-employed traders, from 1 July 2027 (Royal Decree-Law 15/2025). From then on, every invoice must be born as a chained, tamper-proof record with a QR code the tax agency can verify, and the software that issues it has to declare as much.
In OBRASET you never touch that part: the invoice is issued by FACTUSET, our own invoicing engine.
Yes. OBRASET reads FIEBDC-3 files with their full structure: chapters, items, unit-rate breakdowns, texts and measurements with lines and subtotals. It first reads the character set and the decimal places per magnitude declared in the file, and honours them in every recalculation, which is what makes totals agree with Presto or Arquímedes.
When it finishes it shows the diagnostic report: how many chapters, items and prices came in, which mismatches exist between the declared price and the one recalculated from the breakdown, which concepts were left orphaned and which records were skipped without error.
The assistant checks the three requirements of article 91.Uno.2.10º of the Spanish VAT Act, which are cumulative: the customer must be an individual using the home privately or a residents' association, the dwelling must have been completed or renovated at least two years ago, and the materials you supply must not exceed 40 % of the taxable base.
The materials share is computed on its own from the breakdowns and warns from 35 %. Above 40 %, the whole invoice is taxed at 21 %: it cannot be split in two. It also generates the client's statement of responsibility so it stays on file.
No. Issuing the certificate does not trigger VAT by itself. If you collect an advance, VAT is due on the amount collected at the moment of collection (art. 75.Dos of the VAT Act), and OBRASET proposes the advance invoice. On work for a public authority, the chargeable event waits for formal acceptance of the works.
From approved supplier invoices, allocated expenses and site-sheet hours valued at the hourly cost LABORSET publishes for each collective-agreement grade (gross from the wage tables, employer social security, the industry training levy, accrued severance and bonus payments, divided by effective hours).
The table lines up, per chapter, the contracted sale, the planned cost from the breakdowns, what is committed in orders and what has been incurred, with the variance in euros and as a percentage.
It neither numbers nor signs them. It asks FACTUSET, which adds the series, the Verifactu chaining, the QR code, the filing with the tax agency and the signed Facturae file for FACe. Invoices live in FACTUSET, which is where the accounting practice works: that way the firm never needs to go into your jobs to keep your books.
Yes, with one column per document: REA entry, the tax agency certificate under article 43.1.f, social security clearance, the monthly payroll return and the public liability policy. Each cell is a green, amber or red dot according to expiry.
A red document blocks payments to that subcontractor; only an administrator can release them and the reason is recorded. It also keeps the subcontracting register with the three-tier limit of Act 32/2006 and the compliance pack exportable per job.
That is precisely the segment it was built for: from a sole trader with a crew to a fifty-person builder. You can start by estimating and invoicing, and open up certificates, purchasing or compliance when the job calls for it. Nobody should have to deploy an ERP to fit a bathroom.
Yes, with a read-only user and access to all your companies. They get the period's tax returns (303, 111, 115, 130, 349), the accounting export as a SUENLACE.DAT file for a3ASESOR or Sage Despachos, the sector-specific retention-money accounts and the monthly ZIP of invoices with an index. They cannot touch a job or issue an invoice.
And if you would rather we handled the accounting ourselves, we can: there is a law and tax firm behind OBRASET.
These answers are general information, not advice on your particular case. References to Spanish legislation were reviewed on 9 August 2026.
Getting started
The best demo uses your own estimate. Send us a BC3 file or the last estimate you priced, and we will show you how it comes in, how it gets certified and what margin it would have made. Half an hour, over video, no strings.
Would you rather talk? Message us on WhatsApp at +34 681 65 99 55 or write to hola@obraset.es.