Proof of service for building cleaning — digital, tamper-proof, legally watertight.
“We were there, honestly!” isn’t enough. With every complaint, every client change and every contract ending, it’s the proof that decides whether you get paid. Taskey documents every assignment automatically: by NFC scan, GPS, photo and – when needed – with a digital signature.
Why have proof at all?
Complaints cost money. Proof doesn’t.
In day-to-day building cleaning, complaints appear precisely when the client is under pressure themselves – audit due, change of tenant, internal dispute. If you don’t have proof at that point, you pay the price.
A typical case: the property manager claims the staircase wasn’t cleaned on Tuesday. Without proof you have three options: a) redo the cleaning for free, b) issue a credit note, or c) get into a conflict that may cost you the contract.
With digital proof of service, the case is resolved in a minute: NFC scan at 6:32 am, GPS point at the site, name of the cleaner, photo of the cleaned staircase. Discussion over.
- âś“Prevents disputes over delivered vs. invoiced work
- âś“Protects against unjustified credit notes
- âś“Supports client audits and ISO certifications
- âś“Is a requirement for many public tenders
How Taskey proves it
Four pieces of evidence per assignment – automatically.
NFC scan at the site
The employee holds their phone to the NFC tag. Timestamp + tag ID go into the record. Tampering is excluded – the tag is physically on the site.
GPS location
At the moment of the scan, the GPS point is captured. If it’s outside the configured site radius, the entry is flagged and reviewed separately.
Photo evidence
Optional per assignment or per area: before/after photos, photos of critical spots, photos of issues discovered. Every image is signed with time, place and employee.
Digital signature
Where required: the caretaker or client signs directly on the smartphone display – for example for special cleaning or hand-overs. A PDF is generated and sent automatically.
Client access
Build trust instead of inviting complaints.
Taskey Share gives every client their own login with a real-time overview of all assignments at their sites – including proof, complaints function and statistics.
The effect: clients see for themselves that you deliver. Complaints arise less often because trust is higher. And if something does need clarifying, the client has the evidence in front of them – without having to call you.
For you as the owner, this means: fewer follow-up questions, higher renewal rates on contracts and a better negotiating position when renegotiating.
Legal certainty
What matters in court – and where Taskey stands.
Digital evidence is generally admissible in Germany (§371a ZPO), provided it is documented in a tamper-proof way. Taskey meets this requirement with versioned records, cryptographic signatures on every entry, and a complete audit log of every subsequent change.
In a dispute, you can export all relevant evidence as a signed PDF – with timestamp, employee, GPS, photo and, if applicable, signature. Such PDFs are regularly accepted in arbitration and before local courts.
Frequently asked
What owners want to know now.
Is digital proof of service valid in court?+
Yes. Under §371a ZPO, digital records are generally admissible. The precondition is tamper-proofing – which Taskey ensures through versioned, cryptographically signed records and a complete audit log.
Can my staff change the proof afterwards?+
No. Staff can only report an assignment if something unusual happens (e.g. damage found). Changes to timestamps and GPS data are only possible technically via the admin role – with a full audit trail.
How does the client submit a complaint?+
Via the Taskey Share login: they click on the assignment in question, photograph the problem area and add a comment. You see the complaint immediately and can reply directly or trigger a follow-up assignment.
Can I send the proof as a PDF to my client?+
Yes. By site, period or job you export a signed PDF with all evidence, photos and signatures. If you wish, automatically every month on the first of the month by email.
How long is the proof stored?+
By default for the entire statutory retention period (at least 2 years, in many cases 10 years for tax-relevant records) – even after the end of the business relationship with the client.
What happens if a client had access to the wrong sites?+
Every client login is restricted to their own sites. They see neither other customers nor employee master data. You configure visibility in fine detail per role.
Related topics
Keep reading.
Software for Building Cleaning
All-in-one industry software: scheduling, NFC proof of service, time tracking, quotes, invoices, live margins.
Learn moreNFC Time Tracking
Every NFC tap automatically becomes part of the proof of service.
Learn moreTime Tracking for Building Cleaning
How working time is recorded fully and at the same time as proof.
Learn moreHospital Cleaning
Where proof must be especially strict – and how Taskey solves it.
Learn moreTry it free for 30 days.
No credit card, no risk. Set up in 48 hours – Done-for-You by our team.