The provincial government can only spend money approved by the House of Assembly.
In parliamentary language, the House grants supply to the government, as in a supply of money.
Each year, the government asks for interim supply first. That's a portion of next year's planned spending to tide them over from the start of the new financial year until they can get the whole budget passed.
There is no hard and fast rule as to how much the interim supply request is compared to the whole budget. But, if you look at the past eight years or so, you can find one.