Fixed price vs time and materials: the rules that hold up

Fixed price vs time and materials is a legal choice, not just a commercial one, and on consumer work Swedish law treats four different things as four different promises. A fast pris (fixed price) is binding — you carry the overrun. A takpris (capped price, or guaranteed maximum) means you charge the hours you actually use but never more than the ceiling. An ungefärlig prisuppgift (approximate price) is the dangerous middle: under section 36 of konsumenttjänstlagen (the Consumer Services Act 1985:716) it may not be exceeded by more than 15 per cent unless you agreed another limit or you have earned a price supplement for extra work. And if you agreed no price at all, the customer owes a skäligt pris — a reasonable price, judged after the fact by what the job was worth, not by what your invoice says. Which of the four you are on is decided by what you wrote on the quote, so write it deliberately.

The four price models, and which one you are actually on

Most disputes at the final invoice start here. You believe you gave a rough steer. The customer believes they were given a price. Both of you are describing the same email.

Note what is not on that list: “roughly”, “around”, “ballpark”, “a guide only”. Those words do not create a fifth category. In practice they create an ungefärlig prisuppgift, with the 15 per cent rule attached, and you find that out at the worst possible moment.

The 15 per cent rule on an approximate price

Section 36 says that where you have given an approximate price, the stated price may not be exceeded by more than 15 per cent — unless another price limit was agreed, or you are entitled to a supplement for additional work under section 38. Three things about that rule get missed.

• It is a ceiling, not an allowance. Quote 40,000 kr approximate, use 41,000 kr of real work, and you invoice 41,000 kr. You do not round up to 46,000 kr because the law “allows” 15 per cent. Below the ceiling, it still has to be a reasonable price for work actually done.
• The 15 per cent runs on the whole stated price, materials included, unless your quote was explicit that the figure covered labour only. Vague base, wide argument.
• The Act is mandatory in the consumer’s favour (section 3). “This estimate is indicative only and the 15 per cent rule does not apply” does not stick — a term giving the consumer less than the Act does is void. Business-to-business is different: konsumenttjänstlagen does not apply and you contract freely.

The equivalent outside Sweden is the estimate/quote distinction. In the UK a quotation is a firm offer and an estimate is not, but there is no statutory 15 per cent tolerance: an estimate is policed by whether the final charge is reasonable under the Consumer Rights Act 2015, and New Zealand’s Consumer Guarantees Act works much the same way. The Swedish rule is unusually kind to the trader — it hands you a hard, numeric line. Use it as one.

No price agreed at all: the skälighetsbedömning

If nobody said a number, the customer owes a skäligt pris — a reasonable price. The test looks at the nature and scope of the work, how it was carried out, the going rate for equivalent work at the time, and other circumstances. It is a judgement made afterwards, and if it reaches ARN (Allmänna reklamationsnämnden, the National Board for Consumer Disputes) or a district court, the party claiming payment has to show the price is reasonable. That is you.

What makes a price defensible in that assessment:

• Time records made on the day, per technician, per task — not reconstructed from memory three weeks later.
• A published hourly rate that matches what you charge everyone else for the same work.
• Material lines traceable to a supplier invoice, with markup on a consistent, stated policy.
• Photos and a self-inspection record (egenkontroll) showing the scope was real.
• Travel, waiting time and callout charges disclosed before the job, not discovered on the invoice.

An hour you cannot evidence is an hour you will not be paid for. That is the whole reason löpande räkning is where consumer disputes concentrate.

One more mechanic: under section 37 the consumer can demand a specificerad räkning, an itemised bill showing how the price breaks down, and is not obliged to pay until they get one. An invoice reading “electrical work as agreed, 62,400 kr” is not just poor form. It is a bill the customer can lawfully sit on.

The duty to warn: avrådandeplikt and additional work

Section 6 requires you to advise the customer against the work if it would not reasonably be to their benefit, considering the price, the value of the property or other circumstances. The duty applies not only before you start but also if that becomes clear while the work is underway. Translated to price: if you are halfway through a rewire and it is now obvious the job will cost far more than the customer can sensibly justify, you stop and say so, in writing. Section 7 is the penalty — if you should have advised against the work and did not, you can lose the right to be paid for it, in whole or in part.

Section 8 covers tilläggsarbete — extra work you find once the wall is open. You may do it without asking only in narrow cases: where the price is small in relation to the agreed price, or where you cannot reach the customer and there is a risk of serious damage if you wait. Otherwise you ask first. Section 38 is what lets you charge for properly handled extra work on top of a fixed price or beyond the plus-15-per-cent ceiling. No section 8 process, no section 38 supplement.

So the sequence that protects the invoice never changes: discover, stop, tell, price, get a written yes, then work. A message sent after you did the work is not consent. It is a notification.

How to word each model on the quote

Plain wording beats legal wording. A stranger reading it in six months should not be able to honestly claim they thought it meant something else.

• Fixed price. “Fixed price (fast pris): 48,000 kr including VAT, after ROT deduction. Covers the scope listed above. Anything outside that scope is priced separately and only carried out after your written approval.”
• Capped price. “Time and materials with a ceiling (takpris): 745 kr/hour per technician plus materials, total not to exceed 60,000 kr including VAT. If the work looks like reaching the ceiling, we stop and contact you.”
• Approximate price. “Approximate price (ungefärlig prisuppgift): 40,000 kr including VAT. Under konsumenttjänstlagen this may not be exceeded by more than 15 per cent, so the maximum is 46,000 kr, unless you approve additional work in writing. Based on 42 hours, materials per the list below, and no hidden defects in the existing installation.”
• Open time and materials. “Löpande räkning: 745 kr/hour per technician plus materials at cost plus 15 per cent. Estimated 30–40 hours; this is not a price commitment. You get a running total whenever you ask, and we contact you before passing 40,000 kr.”

Two mechanical points. Prices to consumers are stated including VAT — prisinformationslagen requires the total the consumer actually pays, and quoting a net figure to a homeowner is where the argument begins. And if the job qualifies for a ROT deduction, show gross labour, deduction and net side by side, and say plainly that the customer is liable for the full amount if Skatteverket declines the claim. ROT is 30 per cent of the labour cost with an annual per-person ceiling shared with RUT; check the current ceiling at skatteverket.se rather than quoting last year’s figure at a customer. If you would rather not draft any of this from scratch, Hantverkarformuläret — the standard consumer contract published by Konsumentverket with the construction trade bodies — already has these boxes on it.

Then one last check before you send: can the customer tell, from the document alone, which of the four models this is, what the maximum is, and what happens when extra work is found? If yes, the final invoice is a formality. If no, you are relying on goodwill.

The things that lose the argument

• A verbal “yeah, that’s fine” to extra work. It may well be binding. It is not provable.
• An approximate price with no scope assumptions attached to it.
• Rounding up to the plus-15-per-cent ceiling because you are “allowed” to.
• Travel or waiting time that appears for the first time on the final invoice.
• A week’s time log written on the Friday, and a one-line invoice on a job billed by the hour.

Fixed price vs time and materials in 2026

Material price volatility has pushed more firms off fixed pricing and onto löpande räkning, because nobody wants to eat a copper or cable increase between quote and completion. That is rational. But it moves the risk from your margin to your paperwork: the reasonableness test, the approximate-price ceiling and the duty to warn all bite hardest where you bill time. Time and materials without disciplined records is not safer than fixed price. It is the same risk, relocated to the day you send the final invoice.

A workable middle ground on volatile jobs: fix the labour, where you control the variable, and run the material open at cost plus a stated markup, supplier invoice attached. The customer sees the honest reason for the split, and you are not gambling on a metals index.

Either way, the evidence has to be captured as the work happens rather than assembled afterwards — which is the argument for keeping quotes, time, materials and extra-work approvals in one place. OdinTask does that end to end: ROT calculated into the quote, e-signed approval on the scope and on each ÄTA, geofenced time entries, supplier invoices photographed onto the job card. The software is not the point. The point is that by the time you invoice, the reasonable-price argument is already won on paper. More on quoting and ÄTA on the blog; you can run it on a live job from a free trial.