Here you will find an example list of all European VAT numbers.
With this list, you can check if the VAT number you have added to your registration is valid.

Land Code Land Code Example Abbreviation
AT Austria ATU99999999 UID
BE Belgium BE0999999999

N° TVA 
BTW-nr. / MwSt.-Nr.

BG Bulgaria BG999999999 DDS
CY Cyprus CY99999999L FPA
CZ Czech Republic CZ99999999 or
CZ999999999
DIC
DE Germany DE999999999 USt-IdNr.
DK Denmark DK99999999 SE-Nr.
EE Estonia EE999999999 KMKR nr
GR Greece EL999999999 ΑΦΜ
ES Spain ESX9999999X Número IVA
FI Finland FI99999999 ALV-NRO
FR France FRXX999999999 ID. TVA
GB United Kingdom GB999999999 or
GB999999999999 or
GBGD999
VAT Reg No
HR Croatia HR99999999999 PDV ID broj
HU Hungary HU99999999  
IE Ireland IE9S99999L VAT-No
IT Italy IT99999999999 P. IVA, Part. IVA
LT Lithuania LT999999999 PVM MK
LU Luxembourg LU99999999 IBLC Nr.
LV Latvia LV99999999999  
MT Malta MT99999999  
NL Netherlands NL999999999B99 BTW-nummer
PL Poland PL9999999999 NIP
PT Portugal PT999999999 NIPC
RO Romania RO999999999 CIF
SE Sweden SE999999999999 MomsNr.
SI Slovenia SI99999999 ID st. za DDV
SK Slovakia SK9999999999 IC DPH