Simple money transfer with paper trail

Hi,

There are 2 brothers A & B, both are not on talking terms.

A wants B to pay his share of property tax that is jointly levied.

Lets say B's share amounts to X rupees.

How can B send X rupees to A so that both B & A have proof; that

B sent X rupees to A & A received that money.

Please let me know of the simplest methods that leaves paper proof

for both parties (maybe something like RPAD)

Thank you for your time.