9 invoicing mistakes that delay getting paid (and how to fix them)

Most freelancers who get paid late don’t have a client problem — they have an invoicing problem. The money is owed; it’s the process leaking time and cash. Here are the nine invoicing mistakes that keep solos waiting, and the simple fix for each. The full how-to is in how to invoice clients as a freelancer in the EU; this is the “what’s going wrong” companion.

1. Invoicing slowly

The single biggest one. An invoice sent three weeks after the work starts its payment clock three weeks late — and the work is no longer fresh in the client’s mind. Fix: invoice the same day you finish or hit a milestone. Fast invoicing is the cheapest cash-flow upgrade there is.

2. No clear due date or payment terms

“Thanks, here’s the invoice” gives the client no deadline, so it drifts to the bottom of their pile. Fix: state explicit terms on every invoice — “due within 14 days”, a due date, and the accepted payment methods. A deadline turns “eventually” into “by Friday”.

3. Making payment awkward

If paying means copying an IBAN, a BIC and a reference into a banking app, friction delays you. Fix: offer a one-click payment link or easy methods. The easier it is to pay, the faster you get paid — and a multi-currency account lets foreign clients pay you like a local.

4. Missing legally required fields

An invoice without a sequential number, your VAT details, or the right VAT note can be bounced by the client’s accounts team — or your own tax authority. Fix: use invoicing software that templates every required field, so a compliant invoice is automatic. The full checklist is in the invoicing guide.

5. Getting the VAT treatment wrong

Charging VAT when you shouldn’t (or forgetting reverse charge on cross-border B2B) creates disputes and corrections. Fix: know your case — not registered (add the note), domestic (local rate), cross-border B2B (reverse charge) — or let VAT-aware software apply it. Background: EU VAT & OSS explained.

6. Sending a PDF where an e-invoice is now required

For B2B in a growing list of EU countries, a plain PDF is no longer a valid invoice — it must be a structured e-invoice. Send the wrong format and it may simply not count. Fix: check the e-invoicing mandates by country and use software that issues the structured format where required.

7. Never following up

The invoice goes out, gets forgotten by the client, and you’re too polite to chase — so it sits. Fix: follow up on a schedule (a reminder before the due date, on it, and after). Most late payment is inertia; a nudge fixes it. Software that auto-reminds removes the awkwardness entirely.

8. No deposit on big projects

Doing weeks of work before any money changes hands puts all the risk on you. Fix: take a deposit up front (commonly 30–50%) and bill milestones on longer projects, so you’re never fully exposed to a single late payer. Lock it in the contract.

9. Treating invoiced money as money you have

An invoice is a promise, not a payment — counting it as cash leads to spending money that hasn’t arrived. Fix: track paid vs unpaid separately, and look at real received income, not your pipeline. The discipline is part of bookkeeping for solopreneurs.

The pattern

Fix these and the gap between “work done” and “money in the account” shrinks dramatically. Start with the invoicing guide, then pick the tool that enforces it.

Part of the complete EU admin guide for solopreneurs.