Reminding a client about an unpaid invoice without a fight or a lost relationship

The payment deadline passed three days ago and the money hasn't arrived. It feels awkward to write to a client you worked well with, but silence makes it worse: the longer the pause, the harder it gets to bring up money.

Remind them of the facts, without blame

Keep the first message short: the invoice number, the amount, the date payment was expected and the invoice attached. Don't write "you missed the deadline". Most often the invoice got lost with an accountant or went to the wrong person, and a calm tone lets the client simply fix it.

Give one clear next step

End with a specific question: "Could you tell me when to expect payment?" If the client has a problem, it's better to learn about it now and agree on a delay or a partial payment than to guess.

Set the next contact and don't postpone it

If there's no reply, follow up after two or three working days, then call. Put the payment term and the late-payment conditions in the contract up front, so the reminder rests on agreed rules rather than on your mood. Until it's resolved, don't start new work for the same client without an advance.