What's the single biggest reason freelancer invoices get paid late?

Process errors that bounce the invoice from accounts payable: missing PO number, wrong legal name, missing tax ID, or vague line items. Most of these can be eliminated with a saved client template.

Do I need to send the invoice to a specific email at the client?

Yes. Most companies above ~50 staff have a dedicated AP inbox or portal. Sending only to the project contact often delays payment by 1–3 weeks. Ask at project kickoff.

Is sequential invoice numbering legally required?

In the EU, UK, and many other jurisdictions, yes — invoice numbers must be sequential and gap-free. Tax authorities use this to detect missing or duplicated invoices during audits.

Can I send a PDF invoice to EU corporate clients in 2026?

It depends. Several EU countries now mandate structured e-invoices for B2B (e.g. Italy via SDI, France's progressive rollout, Croatia from 2026). Check the client's country requirements — a PDF alone may be rejected.

Should I include a late fee clause even on my first invoice?

Yes. In the EU and UK, statutory interest applies automatically to late B2B payments — but stating it clearly on the invoice from the start improves on-time payment rates and avoids disputes later. See our late payment fees guide.

How do I get the right legal client name?

Always copy it from the signed contract or the PO. Trading names and brand names are not the same as the legal entity that pays the invoice.

Freelancer Invoice Mistakes That Delay Payment

The 10 most common freelancer invoicing mistakes — from missing PO numbers to vague descriptions — and how each one quietly adds days to your time-to-pay.