Press Ctrl + Shift + C on PC, or all four shoulder buttons on console, to open the cheat console
Type testingcheats true and press Enter
Type money 9999999 and press Enter
Type motherlode and press Enter to add 50,000 Simoleons
Type kaching and press Enter to add 1,000 Simoleons
Type rosebud and press Enter to add 1,000 Simoleons
Repeat motherlode as many times as needed
Use household funds cheats with money followed by the amount you want
Save the game after adding money if you want to keep it