You're entitled to take over your OFQ (now Families' Quarter, not OMQ any more, as you don't need to be married to occupy) 2 weeks before marriage iaw the JSP - if you're on the Intranet, you should be able to get access through the Defence Intranet Library. You are NOT entitled to move your spouse-to-be into the property until after your marriage, unless you already have a child from the relationship - then you would be entitled to family accommodation and could make the case for your child's other parent to cohabit (I have seen this happen). You can apply, as a singly, to take on a surplus quarter, subject to the agreement of local management (something I've done myself), but you're not allowed to share it with anyone else - particularly someone who's not in the Service!
That's the official line. In practice, you'll probably get away with moving your spouse-to-be into the house for the 2 weeks before the wedding as long as you don't shout about it (again, I've done it myself). I strongly recommend you don't go for a singly quarter and then cohabit - you will probably get found out...
