Finally a reason to visit the post pffice.

Every one of the 36,000 US post offices around the country will be forced to offer basic banking services — like savings and checking accounts and short-term loans — under legislation introduced Wednesday by Sen. Kristin Gillibrand.

With the bill, the New York Democrat hopes to “wipe out” payday lenders that charge sky-high interest rates.

Post offices, many of which are in under-banked neighborhoods, would also offer debit cards in addition to lower-cost loans, according to an internal memo about the bill obtained by The Post.

“This idea could wipe out the predatory practices of the payday loan industry overnight by providing an accessible and low cost alternative,” Gillibrand tweeted.

The USPS could make loans of up to $1,000 at an annual interest rate slightly above the yield for 1-month Treasury bills — currently about 1.65 percent, according to the memo.

By comparison, the Curo Group, a payday lender, offered loans at an annual rate of 158 percent when it went public in November, according to regulatory filings.

Payday lenders, which typically charge exorbitant interest rates for loans as short as a week, were called “debt traps” by the Consumer Financial Protection Bureau last year — and effectively caused four out of five people to borrow higher amounts just to pay back what they originally owed.

The proposal comes a day after Mick Mulvaney, a major booster of payday lenders, bragged to a Washington audience that he prioritized meetings with lobbyists based on who ponied up the largest donation.

Mulvaney made the comments to banking industry executives, according to the New York Times.

Mulvaney, a former congressman who is now interim head of the CFPB, which regulates payday lenders, vowed to yank a public database of complaints about the financial industry.

Spokespersons for the CFPB didn’t comment.