Professional invoicing for consultants who work across borders.
Manage retainers, project milestones, and multi-currency billing across multiple countries — with VAT-compliant invoices that meet the legal requirements of every client you work with. Enterprise-ready invoicing. Solo-friendly pricing.
Trusted by independent consultants billing clients across Europe, East Africa, and Southeast Asia.
The invoicing problem every international consultant knows
You land a consulting engagement with a client in Germany. Or France. Or the Netherlands. You have done the work. Now you need to get paid.
You open your invoicing tool and send the invoice.
Their finance team sends it back. The German client needs a Leistungsdatum — the date your service was delivered — stated explicitly, even if it is the same as the invoice date. The Dutch client needs your BTW-ID, not your OB-nummer — and if you put the wrong one on the invoice, you have just exposed your personal citizen service number to a third party. The French client needs a SIRET number, a specific TVA phrase if you are under the threshold, and a mandatory late payment clause that French commercial law requires on every B2B invoice.
And if you are managing multiple clients across multiple countries simultaneously — each with different currencies, different VAT rules, and different payment terms — doing this manually is not a compliance problem. It is a full-time job.
Invoicemonk handles it automatically.
Built for every consulting billing structure
Retainer engagements
Set up recurring monthly invoices for retainer clients with automatic scheduling, fixed amounts, and VAT treatment applied correctly for each client's country. Your retainer invoices go out on time, every time — compliant with the mandatory fields required in Germany, France, the Netherlands, or wherever your client is based.
Project-based billing
Invoice by project milestone or deliverable. Each invoice is sequentially numbered, VAT-compliant, and structured for the client's country. If the project spans multiple billing stages, Invoicemonk tracks the full engagement history so you always know what has been invoiced and what remains.
Cross-border invoicing
When you bill a VAT-registered business in another country, Invoicemonk automatically applies the reverse charge mechanism — generating the Article 196 EU VAT Directive notation, including both VAT numbers, and presenting the net amount only. Your EU clients can process it immediately. No back-and-forth with their accountants.
Multi-currency billing
Bill clients in EUR, GBP, USD, CHF, or any currency you agree. The compliance layer works correctly regardless of currency — so a EUR invoice to a German client and a GBP invoice to a UK client both carry the correct mandatory fields for their respective countries.
Your clients are in different countries. Their invoice requirements are different too.
Invoicemonk includes the mandatory fields required by law in each of these markets. Select your client's country and they appear in the invoice automatically.
Germany
Leistungsdatum, Steuernummer or USt-IdNr., Kleinunternehmer exemption phrase, sequential numbering, Stornorechnung for corrections
Netherlands
BTW-ID (never OB-nummer), KVK number, BTW verlegd notation, specific payment due date, KOR exemption phrase
France
SIRET number (14 digits), client SIRET, EI designation, TVA status, franchise en base phrase, mandatory late payment clause
Poland
NIP number, Biała Lista verification guidance, reverse charge in Polish (odwrotne obciążenie), KSeF-ready fields
United Kingdom
UK VAT number, Making Tax Digital (MTD) compatible invoices, reverse charge for cross-border services
Kenya
KRA PIN field, reverse charge under Kenya VAT Act Cap 476, withholding tax notation (20% non-resident WHT)
South Africa
SARS-compliant invoice structure, VAT registration number, zero-rated export notation for foreign clients
All EU countries
Article 196 reverse charge wording, VIES VAT number field, sequential numbering, 15th of month invoicing rule
Managing a client in a country not listed? Invoicemonk applies the international B2B compliance baseline — reverse charge notation, both VAT number fields, and sequential numbering — for any cross-border invoice.
Compliance features that protect your business
Sequential numbering — enforced, not optional
A gap in your invoice number sequence is an audit red flag in every EU country. Invoicemonk enforces sequential numbering at the system level — every invoice gets the next number automatically. Gaps are impossible. Your records are clean whether you invoice two clients a month or twenty.
Reverse charge — correct wording, every time
Cross-border EU invoicing requires specific legal language — the reverse charge notation must reference Article 196 of the EU VAT Directive, include both VAT numbers, and show the net amount only. Invoicemonk generates all of this automatically when you add an EU business client. No research. No wrong wording. No rejected invoices.
VAT exemption handling — across all markets
If you operate under a VAT exemption threshold — Germany's Kleinunternehmerregelung, France's franchise en base, the Netherlands' KOR — Invoicemonk generates the correct exemption phrase for each country in the correct language. Your invoice is compliant whether you charge VAT or not.
Multi-client, multi-jurisdiction management
Every client profile in Invoicemonk stores their country, currency, VAT number, and payment terms. When you create a new invoice for that client, the compliance configuration is already applied. Managing ten clients in five countries does not require ten separate research sessions — it requires one click.
Credit notes — issued without breaking your sequence
When a project is cancelled, a scope changes, or an invoice needs correcting, Invoicemonk generates a credit note that references the original, reverses the VAT correctly, and keeps your sequence intact. Three clean documents in the audit trail — original invoice, credit note, corrected invoice — every time.
Audit-ready records — always
Every invoice is stored with an immutable audit trail, timestamp, and payment status. Run a tax-ready report for any period in seconds. Your records are organised, accessible, and structured correctly for any compliance requirement.
Common cross-border consulting challenges — solved
A client's accountant rejected my invoice and asked for fields I had never heard of.
Invoicemonk builds the mandatory fields for your client's country into the invoice automatically. You never need to know what a Leistungsdatum or a SIRET is — the field appears on the invoice before you can send it without it.
I am not sure whether to charge VAT when billing a client in another EU country.
For cross-border B2B EU invoices, the reverse charge mechanism applies — you do not charge VAT. Invoicemonk detects the cross-border transaction and applies the reverse charge automatically. For domestic invoices, your local VAT rate or exemption phrase is applied based on your registration status.
I manage retainer clients in three different countries with different billing cycles.
Set up each retainer client once with their country, currency, and billing frequency. Invoicemonk generates the correct invoice for each client on schedule — with the mandatory fields for their country, in the right currency, on the right date.
I made an error on an invoice I already sent and deleted it to start over.
Deleting a sent invoice creates a gap in your sequence — which is an audit risk in every EU country. The correct approach is a credit note. Invoicemonk generates credit notes directly from the original invoice, references it correctly, and keeps your sequence intact.
"Your software is good, no reason for me to switch. It does what I need for a fair price. And your support is excellent."
Rico Metzger
Senior Software Engineer — Bulgaria
Invoices international clients across Europe. Renewed specifically for sequential numbering enforcement and correct VAT handling on cross-border EU invoices.
Everything in your Invoicemonk account
Frequently asked questions
Can Invoicemonk handle invoicing for multiple clients in different countries simultaneously?
Yes. Each client profile stores their country, currency, VAT number, and payment terms. When you create a new invoice for that client, the compliance configuration — mandatory fields, VAT treatment, reverse charge notation — is already applied. You can manage clients across ten countries without researching each country's invoicing rules separately.
Does Invoicemonk support multi-currency invoicing?
Yes. Invoice in EUR, GBP, USD, CHF, CAD, AUD, or any currency your client pays in. The VAT compliance fields and country-specific mandatory fields apply correctly regardless of currency denomination.
Can I generate financial reports for my consulting practice?
Yes. Invoicemonk generates tax-ready reports covering all invoices, payments received, outstanding balances, and VAT summaries for any period. Reports can be exported in standard formats for use with your accountant or accounting software.
Is there a plan for consultants who only invoice occasionally?
Invoicemonk Pro at $15/month includes VAT-compliant invoicing, sequential numbering enforcement, reverse charge automation, and country-specific mandatory fields — with no time limit and no feature gates on compliance. Cancel anytime.
Can my clients view their invoice history and payment status?
Yes. Invoicemonk includes a client portal where your clients can view their invoices, check payment status, and download documents. This reduces back-and-forth email and gives clients a professional experience.
How does Invoicemonk handle retainer billing for clients in different countries?
Set up each retainer client once with their country, currency, billing frequency, and VAT treatment. Invoicemonk generates the correct invoice for each client on schedule — with the mandatory fields for their country built in. A German retainer client gets a Leistungsdatum on every monthly invoice. A French retainer client gets the TVA status and SIRET. You set it up once and Invoicemonk handles it from there.
Ready to simplify your international consulting billing?
Join consultants across Europe, East Africa, and Southeast Asia who use Invoicemonk to invoice internationally — with compliance built in from the start.
Get started todayPro from $15/month. Upgrade when you are ready.