Can a bundle be 3 transactions for security level 1?

Question

A bundle has 4 transactions:

• The output; address and amount of IOTA recipient gets.
• The input; address, and amount of IOTA sender gives, and half of their signature.
• The other half of the sender's signature.
• Remaining ouput; if there is left over funds, you have to send it to your own address because IOTA address cannot be spent twice.

A transaction is 2673 trytes, signatureMessageFragment (more info here) has a size of 2187 trytes, and an IOTA signature's length = security * 2187 trytes.

If I am using security = 1, then my signature is exactly the size of signatureMessageFragment.

Does that mean I can tranfer IOTA in a bundle with only 3 transactions?

Answer 1

Yes, you are right.

In case of security = 1 and you are spending all the funds on one address (with no change needed), you can even get away with only 2 transactions (one with the input and sig, and one with the output).