autarc is a heat pump and solar design tool, built in Berlin in 2023 and expanding in the UK. Its strength is design and survey: MCS room-by-room heat loss, hydraulic balancing, emitter sizing, pipework, and LiDAR room scans with automatic radiator detection. Its website also lists a CRM, quotes, invoicing and an AI phone agent, with Lexoffice and sevDesk, both German, for the accounts.
Payaca is the UK-built system the whole job runs on: the enquiry, the quote, the purchase order, the DNO application, the install and the paid invoice sit on one record, with design built in through Glow and Flow (both limited release) or imported from the tool you already use. Here's how they compare for a UK install business, and what each costs at 25 and 40 users.
The short answer
autarc is a heat pump and solar design tool. Choose Payaca if you want the whole job run on one UK record: design with Glow and Flow (limited release) or imports, purchase orders, G98 and G99 applications through ENA Connect, payments and Xero or QuickBooks. autarc fits if specialist heat pump design depth is the main need and the rest of the job runs elsewhere.
- Payaca is best for UK heat pump and solar businesses that want design, MCS documentation, BUS V5 evidence and DNO applications handled in the same system as the job.
- autarc is best for heat pump and solar businesses whose main need is deep design work, such as MCS heat loss, hydraulic balancing and pipework, with LiDAR survey capture, and who run ordering, payments and UK accounts elsewhere.
- Payaca publishes its pricing: Growth, the standard plan for established install businesses, is £1,199/month. Current plans and eligibility are on the pricing page. autarc publishes per-user tiers on a 12-month term, with per-project charges on the lower tiers.
Looking at this yourself?
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Feature comparison
| Feature | Payaca | autarc |
|---|---|---|
| Origin & focus | UK-built, one system for clean tech install businesses | Berlin-built (2023), heat pump and solar design, expanding in the UK |
| Heat pump design | Heat pump estimate in Payaca with Flow (limited release), or import from Heatpunk and Spruce | Built in: MCS room-by-room heat loss, hydraulic balancing, emitter sizing, AI radiator detection, pipework design (Pipeplanning, launched in the UK September 2026) and cooling load |
| Solar design | Design in Payaca with Glow (limited release), or import from EasyPV and OpenSolar | Built in: photogrammetry, shading analysis, module layout, string planning, yield simulation |
| Survey capture | Field app that works fully offline, with job forms, checklists, photos and video saved to the job | LiDAR room scanning with automatic radiator detection, AI floor plan upload, drone photogrammetry (charged per roof) |
| CRM & pipeline | Full pipeline with stage automations, website enquiry capture, all customer activity logged against the project | CRM with lead and customer management, plus an AI phone agent that takes enquiries and fault reports around the clock |
| AI assistant | Agent Dave built in: answers from your account data, drafts proposals and templates, and builds automations you check before they go live. Plus an MCP server for Claude and Cursor | Scotty assistant in the app and on WhatsApp, AI phone agent, supplier invoice reading, with a monthly pool of AI credits and top-ups |
| Quoting & proposals | Branded multi-option proposals. The customer picks options and pricing updates live, signs, and pays the deposit in the same flow | Mobile quote tool with digital signature on site, a customer portal and automatic funding checks |
| Purchase orders & materials | Bill of materials straight from the accepted quote, purchase orders to suppliers, live account pricing and stock with City Plumbing | AI reads supplier invoices into the project. Raising purchase orders and live supplier pricing aren't listed |
| Payments & accounting | Card and bank payment collection, staged payment schedules, Xero and QuickBooks sync | Invoicing, including German e-invoice formats. Accounting integrations listed are Lexoffice and sevDesk, both German. No UK accounting integration and no payment collection listed |
| Scheduling & field work | Calendar and map scheduling, engineer assignment, a field app with travel and labour time logs, and stage rules that stop a job moving on until its forms are done | Planning board and time tracking. Field Worker App for construction documentation and acceptance protocols, usable offline |
| Service plans | Recurring service plans billed through your own Stripe account, with automated invoicing and renewal reminders | Maintenance listed on the entry tier |
| UK compliance | G98 and G99 DNO applications submitted through ENA Connect, prefilled from the project, plus MCS documentation on the job | MCS room-by-room heat loss built in. Grant assistance, grid connection and energy certificates are paid add-ons, and the add-on set still reads German, down to oil tank removal. No UK DNO submission listed |
| Pricing model | Per user. £1,199/mo with 25 users included, or £999/mo on annual billing, then £30 per user (£25 on annual billing). Nothing charged per project | Per user and, on the cheaper tiers, per project too. £39/mo for one user plus £99 per heat pump and £39 per solar job. Unlimited heat pump projects from £199/mo (two users), unlimited heat pump and solar from £349/mo (three users), then £39 per user. Annual-billed rates on a 12-month term |
Origin & focus
UK-built, one system for clean tech install businesses
Berlin-built (2023), heat pump and solar design, expanding in the UK
Heat pump design
Heat pump estimate in Payaca with Flow (limited release), or import from Heatpunk and Spruce
Built in: MCS room-by-room heat loss, hydraulic balancing, emitter sizing, AI radiator detection, pipework design (Pipeplanning, launched in the UK September 2026) and cooling load
Solar design
Design in Payaca with Glow (limited release), or import from EasyPV and OpenSolar
Built in: photogrammetry, shading analysis, module layout, string planning, yield simulation
Survey capture
Field app that works fully offline, with job forms, checklists, photos and video saved to the job
LiDAR room scanning with automatic radiator detection, AI floor plan upload, drone photogrammetry (charged per roof)
CRM & pipeline
Full pipeline with stage automations, website enquiry capture, all customer activity logged against the project
CRM with lead and customer management, plus an AI phone agent that takes enquiries and fault reports around the clock
AI assistant
Agent Dave built in: answers from your account data, drafts proposals and templates, and builds automations you check before they go live. Plus an MCP server for Claude and Cursor
Scotty assistant in the app and on WhatsApp, AI phone agent, supplier invoice reading, with a monthly pool of AI credits and top-ups
Quoting & proposals
Branded multi-option proposals. The customer picks options and pricing updates live, signs, and pays the deposit in the same flow
Mobile quote tool with digital signature on site, a customer portal and automatic funding checks
Purchase orders & materials
Bill of materials straight from the accepted quote, purchase orders to suppliers, live account pricing and stock with City Plumbing
AI reads supplier invoices into the project. Raising purchase orders and live supplier pricing aren't listed
Payments & accounting
Card and bank payment collection, staged payment schedules, Xero and QuickBooks sync
Invoicing, including German e-invoice formats. Accounting integrations listed are Lexoffice and sevDesk, both German. No UK accounting integration and no payment collection listed
Scheduling & field work
Calendar and map scheduling, engineer assignment, a field app with travel and labour time logs, and stage rules that stop a job moving on until its forms are done
Planning board and time tracking. Field Worker App for construction documentation and acceptance protocols, usable offline
Service plans
Recurring service plans billed through your own Stripe account, with automated invoicing and renewal reminders
Maintenance listed on the entry tier
UK compliance
G98 and G99 DNO applications submitted through ENA Connect, prefilled from the project, plus MCS documentation on the job
MCS room-by-room heat loss built in. Grant assistance, grid connection and energy certificates are paid add-ons, and the add-on set still reads German, down to oil tank removal. No UK DNO submission listed
Pricing model
Per user. £1,199/mo with 25 users included, or £999/mo on annual billing, then £30 per user (£25 on annual billing). Nothing charged per project
Per user and, on the cheaper tiers, per project too. £39/mo for one user plus £99 per heat pump and £39 per solar job. Unlimited heat pump projects from £199/mo (two users), unlimited heat pump and solar from £349/mo (three users), then £39 per user. Annual-billed rates on a 12-month term
See it in Payaca
The real product, on our demo accounts.
Compliance & documentation
Generate MCS documents and keep every certificate on the job. More on Compliance & documentation
The whole job in 100 seconds
What you'd actually pay
Headline prices mislead here, because autarc charge per user and, on their cheaper tiers, per project as well. Below is the monthly cost for a team doing both heat pumps and solar, on the cheapest autarc tier that covers unlimited projects for both. These are the sizes where you would genuinely be choosing between the two.
| Your team | Payaca | autarc |
|---|---|---|
| 25 users | £999/mo Growth, 25 users included | £1,207/mo All in One £349 + 22 users at £39 |
| 40 users | £1,374/mo £999 + 15 users at £25 | £1,792/mo All in One £349 + 37 users at £39 |
We're cheaper at both, and we cover more of the job. Their extra seats are £39 against our £25 on annual billing, so the gap widens as you grow.
Their cheap tiers are cheap for a reason. They include one or two users and charge per project: £99 for every heat pump and £39 for every solar job on the £39 entry tier, so ten heat pumps in a month is £39 plus £990. That is a price list built for a surveyor or a two-person outfit, not for a business running installs at volume.
Which is worth holding next to the "all-in-one" claim. We can't find purchase ordering, supplier ordering or payment collection in their published product range, and the accounting syncs listed are Lexoffice and sevDesk, both German packages. For a one-man band that may not matter. For any business with a team and a van fleet, it is most of the week.
Payaca figures above are Growth on annual billing, £999/mo equivalent; the monthly rate is £1,199. If you were incorporated in the last 24 months with eight or fewer employees, Accelerator is £299/mo for the first 12 months. Full detail on our pricing page.
Both columns are annual-billed rates, so the comparison is like for like. autarc's displayed prices default to annual rates on a 12-month term, with a monthly toggle showing higher figures. Their pricing page has separate heating and solar tabs that quote the solar job charge at £39 and £49; their FAQ says that is the yearly and monthly rate, so we have used £39 throughout. Neither column includes one-off onboarding, which is £290 on their side (waived if you start within 24 hours of the demo) and £1,500 on ours. autarc features and pricing taken from autarc.energy, last checked 29 October 2026. Where something is absent from their published range we say "not listed" rather than that it does not exist. Check their current pricing before you decide.
Switching from autarc
Customers, contacts and projects come across from an export of your autarc data, loaded into Payaca through our import tooling and placed at the right stage of your pipeline. Design reports, survey photos and other files go on the project they belong to.
If your surveyors want to keep autarc for heat loss and hydraulic balancing, they can. The design report goes on the Payaca job, and the quote, the order, the DNO application and the invoice run from there.
Growth and above include guided onboarding: we map your workflow, migrate your data and train your team, for a one-off £1,500.
Which is right for you?
Choose Payaca if
- You need the operations half: ordering, materials, payments, accounts
- You want one system from the enquiry to the paid invoice
- DNO submission and MCS paperwork are part of your week
- You have a team and you'd rather not pay per project
Consider autarc if
- Your acute pain is heat loss calculations and survey time
- You want LiDAR capture and hydraulic balancing in the same tool
- You're a small team doing a handful of projects a month
- You already have systems for ordering, payments and accounts
Questions
What's the difference between Payaca and autarc?
They get shortlisted against each other as heat pump software, but design is one stage of a job and it is not the biggest one. autarc is a heat pump and solar design tool covering MCS heat loss, hydraulic balancing, emitter sizing, pipework, LiDAR survey capture and solar layout. Its website also lists a CRM, quotes, invoices and an AI phone agent. Payaca is the CRM, project management and field service system for the whole job, from enquiry to quote to purchase order to install to paid invoice, with design inside it, DNO submission and accounting sync. Think of a job as enquiry, qualification, survey, design, quote, deposit, DNO, compliance paperwork, materials and ordering, scheduling, install, commissioning, invoicing, payment and aftercare. autarc does the design stage well. We do design too, with Glow for solar and Flow for heat pump estimates, both in limited release, and then every other stage.
Which is the better heat pump design tool?
autarc has the deeper heat pump design range on what each of us publishes. MCS room-by-room heat loss, hydraulic balancing and emitter sizing are built into their product, pipework design was added in September 2026, and they publish LiDAR room scanning with automatic radiator detection. Payaca's Flow (limited release, UK) produces the heat pump estimate inside the job, with peak heat loss, heat pump size range, cylinder size and bill savings worked out from the address and EPC, and Glow (limited release) does the design and estimate for solar. We haven't put their design output side by side with ours, so take that as a description of published range rather than a verdict on how well it works. If you prefer Heatpunk or Spruce for heat pumps, or EasyPV or OpenSolar for solar, those designs land on the job too.
Which one handles ordering, payments and accounts?
Payaca. This is the gap that matters when you are choosing solar or heat pump software for a team rather than for one surveyor. Purchase orders raised from the accepted quote's bill of materials, live supplier account pricing and stock, card and bank payment collection with staged schedules, and sync to Xero or QuickBooks. autarc list invoicing, AI that reads supplier invoices into the project, and accounting integrations with Lexoffice and sevDesk, both German; purchase ordering, supplier pricing and stock, payment collection and a UK accounting sync do not appear in their published product range. Design takes a few hours on a job. Ordering, scheduling, chasing payment and reconciling it runs for weeks and touches all the money. That is the part that decides whether the software was worth buying.
Is autarc cheaper than Payaca?
Not at the sizes where you would genuinely be choosing between them. Comparing annual-billed rates on both sides, at 25 users it is £1,207 against our £999, and at 40 users £1,792 against our £1,374, because their extra seats are £39 and ours are £25 on annual billing. Their headline £39 is a different product: one user, and £99 for every heat pump and £39 for every solar job on top (£49 on monthly billing), so ten heat pumps in a month is £39 plus £990. Ask any heat pump software vendor, us included, for the figure at your real user count and project volume rather than the tier price.
Can I use both?
Yes, and plenty of businesses run a specialist design tool alongside us. Designs from Heatpunk, Spruce, OpenSolar and EasyPV come back onto the Payaca project, so the quote, the order, the install and the invoice all stay in one place. Increasingly the design happens in Payaca too, with Glow for solar and Flow for heat pump estimates, both in limited release.
Competitor details are based on their public information as of 29 October 2026. Spotted something out of date? Tell us.