Budgets for Intenal Orders

We have a situation here.

We had created many internal orders in last year and at that time availability control were not activated.

Hence many postings have happened to these orders eventhough no budgets were entered.

Now this year availability control has been activiated.

Do we have to re-enter the budget figures for these old orders created in the last year ?

If we do not enter the budget, will be further postings be blocked by the system for want of budget ?