The last client left at 6 p.m. Instead of going home you sit in front of 12 individual invoices for one person — weekly sessions over three months. Stamp, signature, envelope, post, file, link to bookkeeping. Twelve times. For one client. Consolidated invoicing is the answer — and it is fully legal if you write it correctly.
In brief: A consolidated invoice combines several sessions for one client over a defined period (e.g. one month or one quarter) on a single invoice. Legally it is a normal invoice under UStG — just with multiple service lines instead of one.
When is a consolidated invoice allowed?
Consolidated invoices are generally allowed in Austria if three conditions are met:
- One single recipient — you cannot put two different clients on one invoice
- Clearly delimited period — e.g. month, quarter, treatment phase
- Each service listed separately — date, description, unit price per session
What is not allowed: a single line like „12 sessions of psychotherapy March–May 2026“ without a list of dates. The tax office cannot verify the service delivery, and your client cannot use the invoice for reimbursement.
When does it pay off?
Consolidate
- Regular weekly clients over a longer period
- Self-paying clients without insurance reimbursement
- Client wants monthly or quarterly billing
- Insurance reimbursement to ÖGK / BVAEB / SVS — many funds prefer monthly bundling
- When you want to collect sessions at month end
Bill individually
- Client pays cash after each session
- Acute crisis with only 1–3 sessions
- Diagnostic clarification with unclear treatment course
- Client needs each invoice immediately for insurance or employer
- Per-session fee varies (e.g. self-experience vs. therapy)
What must appear on a consolidated invoice?
All 9 mandatory fields under UStG §11 as on any invoice — plus two specifics:
- Service period instead of service date (e.g. „01.03.2026–31.03.2026“)
- Each session listed with date, description and unit price
For insurance-reimbursable invoices from July 2026 also:
- ICD-10 code for the underlying disorder
- Social security number of the client
- Treatment start date (applies to whole therapy, not per session)
Example: monthly consolidated invoice
Invoice 2026-042 — Consolidated invoice March 2026
Service period: 01.03.2026 – 31.03.2026
| Date | Service | ICD-10 | Unit price |
|---|---|---|---|
| 05.03.2026 | Psychotherapy session 50 min | F33.1 | 110.00 |
| 12.03.2026 | Psychotherapy session 50 min | F33.1 | 110.00 |
| 19.03.2026 | Psychotherapy session 50 min | F33.1 | 110.00 |
| 26.03.2026 | Psychotherapy session 50 min | F33.1 | 110.00 |
| Total 4 sessions | EUR 440.00 | ||
VAT-exempt medical treatment under UStG §6 (1) Z 19. SSN: 1234 010180. Treatment start: 15.01.2026. Net 14 days.
Submitting the invoice to the insurance fund
For out-of-network reimbursement at ÖGK, BVAEB or SVS, consolidated invoices are usually preferred — many funds process monthly bundles faster than 4 individual invoices per month.
What the client submits:
- Original consolidated invoice with all sessions listed individually
- Proof of payment (bank transfer or signed cash receipt)
- Approval form „Application for psychotherapy approval“ (for first application)
The fund reimburses the per-session rate (e.g. ÖGK EUR 33.70 for psychotherapy 2026) — if the invoice is split per session, processing typically takes twice as long.
3 most common mistakes
- Lump line instead of itemised list: „12 sessions at EUR 110“ is not enough. Each session date must appear.
- Different clients on one invoice: Not allowed. One invoice = one recipient. For couples therapy: who is the contracting party? The invoice is issued to that person.
- Wrong service period: If the last session was 30 April, the period must read „01.04.2026–30.04.2026“, not just „April 2026“. Sounds formal, but matters.
Consolidated invoice in TimeInvoicer — in 30 seconds
The workflow:
- Tap the client in the contacts tab
- Pick „Consolidated invoice“ instead of „Single invoice“
- Set the period (e.g. March 2026)
- TimeInvoicer pulls all sessions from the calendar, lists them individually, calculates the total and adds the ICD-10 code from the client record
- Review, export as PDF, done
You don't type anything because all sessions are already in your calendar. You don't number anything because TimeInvoicer knows the next number. You don't even pick the ICD-10 code because it's saved per client.
The result: One consolidated invoice in 30 seconds instead of 12 individual invoices in 30 minutes. At 80 clients per month that saves 6 hours of admin — every month.
One client, one invoice, 30 seconds.
TimeInvoicer turns 12 calendar entries into one consolidated invoice. Try it free, 14-day Pro trial included.
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