Double Cash is a Premium Upgrade for Bloons TD 4 and Bloons TD 5. It costs 24 in BTD4 or 95 before it was removed from BTD5's Premium Store. In the Android and iOS versions of BTD5, it currently costs $9.99 USD in real-world money and cannot be purchased with in-game currency. This mode can be toggled on or off in the premium upgrades store. It doubles the player's starting cash to $1,300, as well as doubling all cash earned for popping bloons during the game. The cash income earned in-between rounds is also doubled, but income from Banana Farm and other income sources is not doubled (except in the mobile versions).
This particular premium is very advantageous because the payout makes Road Spikes less worthless (still will lose money unless the player has Tack Awesomizer), opens up some more room for error, and makes it easier to get powerful towers like the Super Monkey.
In BTD5 Deluxe, it costs 7,500 to fully unlock it. It costs 500 as a one-use powerup in both BTD5 Flash and BTD5 Mobile. In Bloons TD 5 Deluxe, it is available as a toggle on/off option when selecting difficulty. However, high scores are not recorded if Double Cash is used. Also, you will not receive an achievement for beating a map with Double Cash activated, only Monkey Money and a medal. However, in Bloons TD 5 Steam, you have no consequence for using it.
In BTD6, this upgrade makes a return. It costs $17.99 USD (SGD $24.99, 18.99€) in BTD6. However, like in BTD5 Flash, cash gained from extra income sources such as Farms aren't doubled. Do note that Double Cash Mode will always be turned off during C.H.I.M.P.S. and Races as it takes away the whole point of the game mode and it would be considered unfair, respectively.
- The only obtainable way to get it permanently now in BTD5 Flash would be to get the Mega Monkey Everything Pack. The Mega Monkey Everything Pack currently costs 250.
- According to most of the people who buy or want the premiums Double Cash is the most useful one to date.
- With Double Cash and Tack Awesomizer players can make a profit using only Road Spikes due to the fact that Tack Awesomizer makes the Road Spikes pop 22 bloons instead of the usual 11. This can make people Road Spike Farm.
- Double Cash is not possible in Bloons Tower Defense 5 Deluxe for Special Missions or Extreme tracks.
- On Bloons TD 5 mobile and Steam, Double Cash is valid also for the Banana Farm.