With corporate suppliers you can display multiple vendors under one name in Spend. You create a vendor group through this function without actually merging the suppliers (read more about merging vendors here).
There is one drawback when merging the suppliers: when undoing the merging, we always need the spend data again for the year in which you merged the supplier. This is no problem if you always send us the full spend data (of at least the years where the merger took place) with a new delivery. You must also ensure that the years that have been changed by the merger are 'open' in the spend settings. This is not the case with corporate suppliers because the suppliers are not officially merged.
You can find the corporate suppliers you have set in Spend > Vendors > Corporate vendors.