The U.S. Postal Service is raising shipping and stamp prices. Bulk mailing companies say the increase is too high.

The United States Postal Service (USPS) has raised the price of its first-class Forever Stamp, as well as other products, on Sunday, according to USPS Senior Public Relations Representative Marti Johnson, who confirmed the news on Saturday. The new price went from 73 to 78 cents, and took effect Monday.

It’s going to cost you more to send items through the mail, starting Sunday. The cost of a U.S. postage stamp goes up five cents, from 73 to 78 cents. The price hike is part of wider 7-point-four percent increase in services that includes forever stamps,