Invitation cards must contain the essential details such as venue, time, location etc. I would suggest that you keep the invitation short and sweet. Start by saying that you would like to thank everyone for the years of service, cooperation and support they have provided you and would like to announce the opening of your new office and then mention the new location of your new office. You can then continue by inviting them for the puja and ask your invitees for joining you for lunch or a party (if you are planning anything of the sort).

Further, mention the time of the puja. You could put a concluding note by saying “we look forward to your presence” or on a similar note. Anybody has any other suggestions?