Can I charge interest on a late invoice in South Africa?

Only if you said so upfront. The Prescribed Rate of Interest Act sets a default rate you can charge once a debt is legally due, but courts and clients generally expect that right to be stated in your quote or terms before the job starts — not added retroactively once payment is already late. Add a late-payment clause to future quotes rather than trying to apply one now.

Why would a client refuse to pay an invoice?

The single most common reason isn't dishonesty — it's that the invoice is missing a field SARS requires for a valid tax invoice (like the supplier's VAT number or a proper description of the goods or services), which gives a hesitant payer a genuine, defensible reason to hold the payment until it's reissued.

When should I send the first payment reminder?

Before the due date, not after. A short heads-up sent 2-3 days before an invoice is due reads as organised, not pushy, and catches the invoices that were simply going to be forgotten in an inbox.

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Invoices & getting paid

How to follow up on a late invoice without losing the client

Zuvo Team20 September 20266 min read

Short answer: most late payers aren't dishonest, they're disorganised — the invoice got buried, not refused. A scheduled sequence of four messages, sent on a fixed timeline and without apologising for asking to be paid, gets money in faster than one awkward WhatsApp sent three weeks too late.

Why chasing payment feels so much worse than it is

For a small business, the client on the other end of that invoice is often someone you'll work with again, or someone who found you through a referral you don't want to burn. That relationship makes every follow-up message feel like a confrontation, so most owners either wait too long to send it, or send something so soft it reads as optional. Neither works. The fix isn't a harder tone — it's removing the awkwardness by making the follow-up scheduled and expected, not a one-off confrontation you have to work up to.

The four-stage sequence that actually works

Set these on a calendar the day you send the invoice, so sending them stops being a decision you have to make each time:

2-3 days before the due date — the heads-up. Not a chase, a reminder. This alone recovers a surprising number of invoices that were simply forgotten, not disputed.
On the due date, if unpaid — the nudge. Friendly, assumes good faith, gives them an easy way to flag a problem if there is one.
7 days late — the firmer message. Restates the terms and the amount plainly. Still professional, no longer purely casual.
14+ days late — the direct message. States a clear next step and a date, so the client knows what happens if it goes further.

What to actually write at each stage

Heads-up (before due): "Hi Nomsa — just a heads-up that invoice #0142 for R4,200 is due Friday. Let me know if you need anything from me to process it."

Nudge (due date): "Hi Nomsa, invoice #0142 (R4,200) was due today — I don't see it reflecting yet. Could you confirm when it'll go through? Happy to resend if it got buried."

Firmer (7 days late): "Hi Nomsa, following up on invoice #0142, R4,200, due 15 September — it's now a week overdue. Could you give me a firm date for payment? I'd like to keep things on track for the next job."

Direct (14+ days late): "Hi Nomsa, invoice #0142 (R4,200) is now two weeks overdue with no response to my last two messages. I need payment by Friday 26 September to avoid pausing further work / adding late-payment interest per our agreed terms. Please confirm by then."

Notice what doesn't change across all four: the invoice number and amount are stated every single time. Never make a client hunt for what they actually owe.

Check the invoice itself isn't the real problem

Before assuming a client is stalling, rule out the most common genuine reason a payment gets held up: an invoice that doesn't meet SARS's tax invoice requirements. A missing VAT number, an incomplete description of the goods or services, or a missing invoice date all give a hesitant payer — or their bookkeeper — a legitimate, defensible reason to sit on it until it's fixed. If you're VAT-registered, every invoice needs your VAT number, a unique invoice number, the date, a proper description of what was supplied, and the price including VAT shown clearly. Reissuing a compliant invoice often resolves a "late" payment faster than any follow-up message will — see the full breakdown of what's required at each sale value if you're not sure which fields apply.

What South African law actually lets you do

You can charge interest on an overdue invoice under the Prescribed Rate of Interest Act — but only if you said so upfront. Adding an interest threat to a quote or invoice after the fact tends not to hold up, and it reads as bad faith to a client who never agreed to it. The fix is forward-looking, not retroactive: add a simple line to future quotes — "Payment due within 14 days. Overdue accounts are subject to interest at the prescribed legal rate." — so the next late payment gives you real leverage from day one.

Keeping track of which invoices are even overdue gets harder as the list grows — here's what proper invoice tracking should do instead of a spreadsheet.

Zuvo drafts the reminder sequence and the compliant invoice, in your tone

Describe the situation and Zuvo writes the next message in the sequence — or a properly formatted tax invoice from your price list — ready to send.

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General business advice, not a substitute for advice from your own accountant or attorney on debt collection or tax invoice compliance specific to your situation.