A VAT payer is a business registered for value added tax. Such an entity adds VAT to its prices but can also deduct the VAT on its purchases.
A company that is already a VAT payer saves you time — you do not have to wait for a voluntary registration at the tax office. This is especially valuable when trading with other VAT payers or making purchases with higher VAT.
On the other hand, if you mostly sell to end customers with no right to deduct, being a VAT payer may not be an advantage. Consider your type of business.