Client billing · 7 min read

New client billing setup: what to agree before the first invoice

Almost every payment delay is created before the first invoice exists. Ten minutes of questions at the start of an engagement removes most of them.

A billing setup checklist completed at the start of a client engagement

Chasing an invoice is expensive work: it takes time, it is unpleasant, and it happens at exactly the moment you least want to be talking about money with a client. The alternative is not better chasing. It is asking a short list of questions before any work starts, when both sides are enthusiastic and nothing is contentious.

Worked example

A worked onboarding message

This does not need to be a form. One email works:

Step: The full registered entity name and billing address for invoices
The best email address for sending invoices: an accounts inbox if you have one
Step: Whether a purchase order will be raised, and the number once it is
Step: Whether there is a supplier setup form I should complete now
Step: Your payment run dates, if invoices are processed on a fixed cycle

Original diagram

New client billing setup: what to agree before the first invoice workflow

1Why this conversation is easy at the start and hard later
2The questions that matter
3What you should state in return
4Judging risk proportionately

Why this conversation is easy at the start and hard later

At the beginning of an engagement, questions about billing are read as professionalism. The client has just decided to work with you, and someone asking how their invoicing process works looks like someone who has done this before.

The same questions asked eight weeks later, with an invoice overdue, are read as an accusation. The information is identical; the framing is not.

The questions that matter

Who exactly am I billing?:

The registered legal entity name and billing address, not the trading name. Large organisations often run many entities with near-identical names, and the one you are dealing with may not be the one that holds the contract. Billing the wrong entity is one of the few errors that cannot be patched — it usually means cancelling and reissuing.

Who processes invoices, and where do they go?:

Get a name and an email, or the address of the accounts payable mailbox or supplier portal. Sending invoices only to your day-to-day contact is one of the most common reasons an invoice never enters the client's system at all. Copy your contact by all means, but the invoice needs to reach whoever actually processes it.

Will there be a purchase order?:

If yes, you need the number before you invoice, and your invoice must quote it exactly. If no, ask what reference their process expects instead — a contract number, a project code, or the name of the approver.

When do you run payments?:

The question almost nobody asks, and often the one that matters most. Many organisations pay on fixed dates with a submission cut-off some days before. An invoice sent two days after the cut-off waits for the next cycle, which can mean four extra weeks regardless of your stated terms.

Is there supplier onboarding to complete?:

Forms, bank verification, compliance checks, portal registration. These can take weeks at large organisations, and an invoice from a supplier who is not yet set up cannot be paid. Start this at the beginning of the engagement, not when the first invoice is due.

What do you need shown on the invoice?:

Tax identification numbers, cost centres, project codes, particular wording. Cheap to include if you know; expensive to discover after an invoice is rejected.

What you should state in return

Onboarding runs both ways. Confirm in writing:

Your payment terms and how the due date is calculated
Your billing rhythm — on completion, monthly in arrears, on milestones
What is billable beyond your fee, and any approval thresholds for expenses
Any deposit and what it triggers
How scope changes are priced — the single biggest source of later disputes
Your bank details, and that they will never change by email. Say this once at the start and it protects both of you against impersonation later.

Judging risk proportionately

How much diligence to do depends on what you are exposed to:

Small job, paid on completion — the questions above are enough.
Large project with upfront costs — add a deposit, and consider a basic check on how long the business has been trading and whether public filings are current.
Long engagement with a new client — stage the billing so you are never carrying more than one period's work unpaid.
Any client who resists confirming basic billing details — treat the resistance itself as information.

Keep the record

Store the answers somewhere you will actually look: entity name, billing email, PO requirement, payment run dates, agreed terms. Review it whenever your contact changes, because billing contacts turn over frequently and an invoice sent to someone who left six months ago is invisible rather than late.

None of this is complicated. It is simply front-loaded, which is why it so often gets skipped — and why the businesses that do it consistently spend so much less time chasing.

Common questions

Helpful clarifications

What billing details should I collect from a new client?

At minimum: the exact registered legal entity name and billing address, the name and email of whoever processes invoices, any tax identification number they need shown, whether a purchase order will be raised, and where invoices should be sent. For larger organisations, also ask about payment run dates and submission cut-offs, since those often determine when you are paid more than your terms do.

Why does the exact legal entity name matter?

Because an invoice addressed to the wrong entity often cannot be paid at all, and correcting it usually means cancelling and reissuing rather than editing. Large organisations frequently operate many registered entities with similar names, and the brand you deal with may not be the one that holds the contract. Ask which entity is contracting, and confirm it in writing.

Should I credit check a new client?

It is proportionate for large engagements or where you are carrying significant costs upfront. Formal credit reports are available in most markets, but simpler checks go a long way: how long they have been trading, whether public filings are up to date, and whether other suppliers report being paid on time. For smaller jobs, a deposit achieves more protection than a report would.

What if the client asks me to complete their supplier onboarding forms?

Complete them before you start work, not when your first invoice is due. Supplier onboarding at large organisations can take several weeks, and an invoice from a supplier who is not yet set up in their system cannot be paid regardless of how correct it is. Treat the onboarding form as part of the engagement, not as paperwork to deal with later.

How do I ask these questions without sounding distrustful?

Frame them as setup rather than scrutiny. A short message saying you want to make sure invoices reach the right place and get processed smoothly reads as organised, not suspicious. Most billing contacts are relieved to be asked, because supplier invoices that arrive incorrectly addressed create work for them too.