Historical clue formulations

• Stamp on an invoice — 2025-05-18
• Ponied up — 2024-06-05
• Settled up — 2024-04-11
• Taken care of, on an invoice stamp — 2023-09-11
• Shelled out — 2023-08-02
• Ponied up — 2022-12-08
• Was worthwhile, with "off" — 2022-08-28
• Stamp on an invoice — 2021-06-14
• Not outstanding — 2020-04-26
• Red stamp word — 2020-04-25
• Forked over — 2019-04-21
• Word stamped on an invoice — 2018-05-01
• Accountant's stamp — 2017-05-04
• Bookkeeper's stamp — 2016-07-08
• Like the best kind of vacation — 2016-04-05
• Not working as a volunteer — 2015-07-12
• Not free — 2015-01-18
• With 15-Down, spent way too much money for something — 2014-04-17
• Accountant's stamp — 2013-11-21
• Invoice stamp — 2013-05-07
• Settled up — 2013-04-17
• Took care of, as bills — 2012-11-12
• No longer owed — 2012-01-16
• Took care of, as a bill — 2011-10-04
• Covered, in a way — 2009-09-13
• Office stamp — 2008-12-27
• Bill stamp — 2007-01-16
• Settled up — 2007-01-08
• Coughed up — 2006-10-08
• Stamp with a date — 2006-04-28
• Settled, as a bill — 2006-03-20
• Invoice stamp — 2004-07-13
• Settled — 2003-11-28
• Put up the cash — 2002-09-13
• Receipt stamp — 2001-11-28
• Nice word to see on a bill — 2001-05-19
• Invoice stamp — 1995-04-20
• Invoice stamp — 1994-10-11