Vat only invoice

[missinggreenfields]

Four step process:

1) Ask them why they want to do this.
2) Run a credit check on them.
3) Make sure you have business interruption insurance.
4) Hope that they don't disappear with your money.

I'd do all of those concurrently.

[Maslins]

My first thought on reading the OP was that perhaps your own company didn't have VAT registration properly in place when sending your first invoice. They therefore dealt with you as a non VAT registered entity. Since then they've realised you were VAT registered at the time, so need to correct their records, in which case easiest way for them would be for you to send a VAT only invoice as they've suggested.

However, some other possible reasons above...so I think you need to clarify what the situation is.