Litigation and Dispute Resolution Q&A

I assume you have had enough contact with them that there is no doubt this amount is neither overlooked nor disputed.  So it depends on the commercial value of the client to you:

1. This is the only invoice.  Send a letter advising legal action if not paid within 7 days.  They will either pay or not.  If they don't, write the debt off and move on.  Spending more time and money on a small, slow-paying client is just not worth it.

2. You have ongoing business for a reasonable amount with them.  Send a letter / email advising that your policy is to do no further work for clients with bills 90+ days overdue so their account has been suspended.  They need to pay within 7 days.  All future work will require a deposit in advance / be on a 7 day payment term.

3. You have no business at present but hope for some in the future.  Build it into the pricing for the future work and make sure the payment terms on that future work are cast-iron including an advance payment, and that they sign for the work before you start doing anything.

Including a clear statement of payment terms in your T&C is also a good idea.

BTW I once had a client who only ever paid on receipt of a 7 day warning letter.  Non-payment was clearly a cashflow management issue for them and the 7 day letter acted as a warning to them that it was time to stop resisting and pay up.  Once I knew the pattern I just made sure they got 7 day letters at 60 days when other clients didn't get them till 90 days.