on the slate

on the slate

1. Still to come; scheduled to occur. This victory should give a much-needed boost to the team's morale, as they have three more crucial games on the slate.
2. old-fashioned On credit (as opposed to being paid for upfront). A slate was formerly a stone tablet on which a customer's bill was tallied and then wiped clean once the debt was paid. Primarily heard in UK. Go around to Tom Buchanan's shop and get these fixings for supper. Tell him to just put it on the slate.
See also: on, slate
Farlex Dictionary of Idioms.

on the slate

BRITISH, OLD-FASHIONED
If you buy something on the slate, you have it now but promise to pay for it later. Note: In the past, people used pieces of a dark grey stone called `slate' for writing on, for example in schools, shops, and pubs. Shopkeepers and pub owners would write customers' debts on their slates, and wipe them clean when the debts were paid. If a man was unemployed at the time, some kindly shopkeepers would put it `on the slate' until the next payment came.
See also: on, slate
Collins COBUILD Idioms Dictionary, 3rd ed.

on the (or your) slate

to be paid for later; on credit. British
Shops and bars formerly kept a record of what a customer owed by chalking it on a tablet made of slate.
See also: on, slate
Farlex Partner Idioms Dictionary

(put something) on the ˈslate

(informal) (put something) on your account in a shop, a bar, etc. to be paid for later: Can I put this on the slate?
A slate is a thin sheet of a type of dark grey stone that was used in the past to write on.
See also: on, slate
Farlex Partner Idioms Dictionary
See also:
  • on (one's) slate
  • go online
  • Sufficient unto the day is the evil thereof.
  • thereof
  • to good effect
  • to good, little, etc. effect
  • a little too late is much too late
  • under normal circumstances
  • talk around
  • talk round
References in classic literature
When my sister found that Biddy was very quick to understand her, this mysterious sign reappeared on the slate. Biddy looked thoughtfully at it, heard my explanation, looked thoughtfully at my sister, looked thoughtfully at Joe (who was always represented on the slate by his initial letter), and ran into the forge, followed by Joe and me.
Great Expectations
She did it so quickly that the poor little juror (it was Bill, the Lizard) could not make out at all what had become of it; so, after hunting all about for it, he was obliged to write with one finger for the rest of the day; and this was of very little use, as it left no mark on the slate.
Alices Adventures In Wonderland
Hester Dethridge wrote slowly on the slate, in singularly firm upright characters for a woman in her position of life, these words:
Man And Wife