How to do in case of mistake in issuance of 2 separate tax invoices – double invoice sequence number?

The company mistakenly issued 2 tax invoices (with the same sequence number)  for two separate customers. In case one of the customer uses the tax invoice to claim VAT already, does it mean that the other customer does not need to use the tax invoice. How to do for this case?

Panwa : For this matter, the company must cancel the other tax invoice that has not yet been used to claim VAT  and issue a new tax invoice (with the same date, but with the correct tax invoice sequence number) to the customer. If you need further assistance for monthly tax filing, kindly note that we could assist for such, click here.

For more information, please feel free to contact us:
Phone: +66 2 933 9000
Fax: +66 2 933 6120
Email: bkk@panwa.co.th

For more information, please feel free to contact us:

Office: +66 2 933 9000
Whats'App: +66 8 5713 1000
Email: bkk@panwa.co.th

Location: https://goo.gl/maps/MhJsbjkPrji51Qyt6
Sky train: Yellow Line, Chokchai 4 Station, Gate 4. Our office is located between Soi Latphrao 50 and 52.

Address: 1560 Latphrao Road, Wangthonglang, Bangkok 10310, Thailand.