Terms of use and of sale

1. Who you are dealing with

SyntaxFlow is operated by Elam Uceda Herrero, a sole trader established in Spain, trading under the name SyntaxFlow, at Calle Fresnedillas 25, 28035 Madrid, Spain. Spanish tax identification number (NIF): 48228797M. Contact: see below.

The site is published in association with HU Ingenieros, the Madrid software company described on the about page. HU Ingenieros is not a party to your purchase — the payment, the invoice and the refund are all with the trader named above.

United Kingdom. In the United Kingdom we sell Pro and the Plan Taller only to businesses, not to private consumers, because we are not registered for VAT there.

2. What the free part covers

Every calculator on this site is free to use, with no account, for any purpose including paid professional work. Creating an account, which is optional, changes none of this. You may quote the results in your own documents, you may keep them, and you do not owe us attribution. There is no usage limit and there is no fair-use clause waiting to be invoked against you.

The document tools (estimate, job report, survey sheet and the rest) are free too, with the limits the pricing page lists. Among them, the free plan saves up to 10 new documents a month among estimates, job reports, survey sheets, delivery notes and purchase orders; editing, printing and exporting what you have made never counts and is never blocked, and with Pro there is no monthly limit.

What you may not do is copy the site itself — the pages, the text, the layout and the implementations behind the calculators are ours, and republishing them, or scraping them into another product, is not covered by the above. Using a result is fine. Taking the tool is not.

The one exception is the embed code offered on /embed/: with it you may show our calculators on your own website, free, as long as the attribution link stays as it is and visible. They are provided without warranty (section 8 applies to them as to this site), and we may change how embedding works or stop offering it.

3. What you are buying with Pro

Pro is bought with a single payment of €29, tax included, which is not a subscription: there is nothing to renew and nothing to cancel. Until 11 November 2026 the same Pro could also be paid as a monthly subscription of €3.99; it is no longer sold, and section 5 keeps its terms for whoever subscribed before that date.

What it covers, in full, so that this clause and the pricing page describe the same product: on every calculator, the report with your logo and company details and no SyntaxFlow line, lists and saving without limit, and the Excel file; the glazing schedule checker on every project, with every line, the fewest make-ups, the order list, the handling plan, the project report and the comparison of revisions (the first three projects can be checked in full without paying); for the cutting table, a printed label for every pane in a job rather than the first twelve, an offcut rack of 400 pieces rather than 25 and the job library; and your own footer line in place of ours on the documents and labels you print.

Being precise about the limits, because this is where a customer could reasonably feel misled:

• Pro does not change any calculation. Every number is identical before and after paying.
• Pro does not unlock any calculator. Nothing on this site is behind the payment; all of it was already free.
• Pro does not add a warranty and does not make a result a signed calculation. Section 8 applies to paid and unpaid use alike.
• If you pay without an account, the unlock is stored in the browser you bought it in and does not travel with you to another machine by itself; if you lose it, it can be restored — see section 7. If you pay while signed in, Pro is kept in your account and recognised on every device where you sign in. The same goes for a monthly subscription started before 11 November 2026, taken with or without an account.

Pro covers the calculators, the cutting optimizers and the document tools for the trade (budgets, survey sheets, job reports, checklists, price lists, dossiers and the like), including the ones we add later in those areas: with the €29, for as long as the site exists and with no further payment; with the monthly, for as long as the subscription runs. Products for households are separate and are not part of Pro.

4. Your account

Optional. You need an account only to have Pro recognised on any device and to sync your work between your devices. Without one, everything else works as section 2 describes.

Who may open one. Adults aged 18 or over, one account each, with a username and a password. Keep your password and your recovery code to yourself: whoever has them can enter your account. We keep neither in readable form, so we cannot tell you your password; to get back in you use the recovery code or, once recovery emails are switched on and if you added an address, your email. If you lose the password and the recovery code and have not added an email, we may not be able to give you the account back.

What you put in it. What you sync stays yours. You allow us to store it and to send it back to your devices, which is all we do with it. You are responsible for having the right to store what you sync — your customers' details in a budget, or what you add about your family in Family.

Fair use. Do not use the account to store unlawful content, to attack or overload the service, or to reach other people's data. Sync has storage limits per account (today, 25 MB of data and 250 MB of files); beyond them the account accepts nothing more until there is room again. We may suspend an account that breaks these rules, and will tell you why unless the law or security prevents it.

Sync is a convenience, not a backup. We look after what you sync, but keep your own copy as well: My data saves everything to a file on your device.

Leaving. You can download everything and delete the account at any time from your account page. If we ever decided to close accounts altogether, we would say so on this site at least 60 days in advance and keep the download working until then; a running monthly subscription would stop being charged.

5. Pro monthly (no longer sold)

No longer sold. Pro monthly stopped being sold on 11 November 2026. These terms stay in force for the subscriptions started before that date.

What it is. The same Pro as section 3, paid each month from the monthly page. These are its terms.

Price and charge. €3.99 a month, tax included, charged by Stripe. The first 7 days are not charged: Stripe asks for the card when you subscribe and makes the first charge on day 8, then every month, until you cancel. If you cancel within those 7 days, nothing is charged.

With or without an account. With an account, the subscription is kept in it and Pro is recognised on every device where you sign in. Without one, Pro is kept in the browser you subscribed in; on another device you get it back with the email you paid with and the last four digits of the card (section 7).

It renews by itself. Each month the subscription renews and is charged again until you cancel. We say so here, on the pricing page and on Stripe's payment page, so that it is never a surprise.

Cancelling is as easy as subscribing. Cancel whenever you like, online: by writing to the support address, or yourself on Stripe's customer page, linked from the monthly page and from your account page. There is no penalty and no notice period. Cancelling stops future charges; Pro stays on until the end of the period already covered (the 7 days not charged, or the month already paid), and then ends.

If a payment fails. Stripe tries again for a while, and Pro stays on for three days after the month already paid while it does; if the payment still fails, the subscription ends, and Pro with it. Nothing you saved or synced is deleted when Pro ends: the tools go back to the free limits.

Price changes. A new price never applies to a month already paid. If the price changes, we will tell you at least 30 days in advance at the email address you gave Stripe, before the first charge at the new price, and you can cancel before then.

Withdrawal. You may withdraw within fourteen calendar days of subscribing, without giving a reason and even if you have used Pro: use the withdrawal page or write to the support address. When you subscribe, you ask for Pro to start straight away. The first 7 days count within the fourteen. If you withdraw within those 7 days, nothing has been charged and the subscription simply ends; if you withdraw later within the fourteen days, we refund everything charged and the subscription ends. After the fourteen days, cancelling stops future charges and the month already paid is not refunded.

5a. The Plan Taller

What it is. Everything in Pro (sections 3 and 5), plus the photos and files of your surveys and job reports synced between your devices and kept in your account. It is bought from the Plan Taller page and needs an account (section 4).

Price and charges. €19 a month, tax included, charged by Stripe. The first 7 days are not charged: the first charge is on day 8, and then every month until you cancel. It renews by itself; cancelling, price changes, failed payments and withdrawal work exactly as for Pro monthly (section 5), at this price.

Where the photos and files are kept. In your account, in Cloudflare storage in the European Union, only to sync them for you (see the privacy policy). Each account holds up to 250 MiB and 2,000 files, and each file up to 25 MiB.

When the Plan Taller ends. If you cancel or stop paying, the plan stays on until the end of the period already paid. After that, photos and files stop syncing, and the ones in your account are kept for 30 days in case you take it again; after those 30 days they are deleted from our storage. What is on your own devices is not touched, and your documents keep syncing as with any account. To keep the account's copy, download the files first from a synced device or with your account's data export.

Your customers’ data. What you keep in your account with data about your customers, suppliers or staff (with syncing or the Plan Taller) we process on your behalf, only to sync it for you, under the data processing agreement (Article 28 GDPR), which forms part of these terms and is accepted with them.

6. Payment, tax and the invoice

Payment is taken by Stripe. We never see or hold your card details. The €29 (or the €3.99 each month of a subscription started before 11 November 2026) is the total you pay; any applicable VAT is already inside that figure. If you are a business, enter your VAT number at checkout and the invoice will reflect it.

A PDF invoice is generated automatically and sent to the email address you give at checkout, along with a receipt. If either fails to arrive, ask us and we will resend it. For the monthly subscription, Stripe sends an invoice every month.

How the purchase is made. You choose Pro on the pricing page; for a monthly subscription started before 11 November 2026, you chose on the monthly page whether to sign in first, and you ticked there that you asked for it to start straight away. Stripe's payment page then shows the product and the price (for that monthly it also showed that the first 7 days are not charged and that it renews each month); you can review and correct every field there before the final button, which commits you to pay. Afterwards you land on our confirmation page, and Stripe emails you the receipt and the invoice. If you are signed in, the purchase is kept in your account. The version of these terms that applies is the one published on the day you paid. The contract can be made in English or in Spanish. If the versions of these terms in different languages ever differ, the Spanish version prevails; the others, this English one included, are translations for information.

7. Withdrawal, refunds, and losing your unlock

Fourteen days to change your mind. Pro and the Plan Taller are digital services. If you paid the €29 once, you may withdraw within fourteen calendar days of buying, without giving a reason and even if you have used Pro: use the withdrawal page or write to the support address. We refund the full €29 to the same card within fourteen days of hearing from you, and Pro stops. Before paying, you tick a box asking for Pro to start straight away; that does not take this right away. We apply the same rule to business customers, although the law does not require it. (This is the €29 one-off payment; for the monthly and the Plan Taller, see section 5.)

If it does not unlock. If you are charged and Pro does not unlock, not even with the unlock page, write to the support address: we fix it or refund the €29 in full. The same if you are charged twice by mistake. If Pro does not do what this site describes, you keep the rights the law gives you for lack of conformity.

If you lose the unlock — new laptop, cleared browsing data, a fresh browser profile — email the support address from the address you paid with and we will restore it. You can also do it yourself on the unlock page, with the email you paid with and the last four digits of the card. If you have an account and restore it while signed in, the purchase is kept in the account and recognised on every device where you sign in.

8. What these tools are, and what they are not

Everything on this site is a pre-dimensioning and screening aid. It is for deciding what to specify, for checking whether a quoted figure is plausible, and for understanding where a number comes from. It is aimed at people who already know the subject.

It is not a structural calculation, not a building-physics report, not a compliance certificate, and not professional advice. We are not acting as your engineer. Before anything is ordered, manufactured, installed, or submitted to an authority, the responsible engineer must do their own calculation against the code that actually applies to that project, in that country, for that building.

Standards are cited so you can check our working against the source, not to claim certification against them. Where a tool follows a withdrawn standard, or a simplified method, it says so on its own page. Coefficients, load cases and national annexes vary; ours are the common ones, not necessarily yours.

9. Liability

The tools are provided as they are. We do not warrant that a result is correct for your situation, and we do not accept liability for loss arising from relying on one — including material ordered, work carried out, or a quotation given on the strength of a number from this site. If you use a screening tool as if it were a calculation, that decision is yours.

Where liability cannot lawfully be excluded — death or personal injury caused by negligence, fraud, and the rights consumers have under mandatory law — nothing here limits it. For everything else, and to the extent the law allows, our total liability to a paying customer is capped at what that customer paid us.

We do not promise the site will always be available. The calculators are static pages, which makes them unusually reliable; the account and sync depend on a small server and may be unavailable at times. Neither is a service you should schedule work around.

10. Your data

What you type into a calculator is worked out in your browser and is not sent while you calculate. If you create an account and switch on sync, the work your tools save is copied to your account. The privacy page sets out the whole picture — analytics, what is stored in your browser, what the account keeps, who helps us run it, and what Stripe receives when you pay.

11. Changes to these terms

We may change this page. The version that applies to a purchase is the one published when you paid, and we will not apply a later change retroactively to something you have already bought. For the account and the monthly subscription, which go on over time, a change applies from the next month at the earliest, and only after we have announced it on this site and, for the monthly, at the email address you gave Stripe; if you do not agree, you can cancel or delete the account before it takes effect. The date at the top says when it last moved.

12. Law and disputes

Spanish law applies and the courts of Madrid have jurisdiction. If you are a consumer resident in the EU, this does not take away the protection of the mandatory rules of your own country, nor your right to bring a claim there.

13. Contact

Support is answered by the same people who wrote the calculators, which is both the good news and the bad news: replies are informed, and they are not instant.