Invoice number gap

Hi Dears,

In one of our plant, after invoice no 110000296 next invoice no got generated as 110000311.

When we checked the invoice no 110000297, 298, 299....310 the invoice relates to 31.12.2006.

What could be the reason for this invoice gap.

We are maintaining Plant wise number ranges.

Thanks in Advance.

Regards,

Sankar