Green’s Dictionary of Slang

to pay over money, to pay on demand.

1821		‘An Amateur’ Real Life in London I 559: Many a twelver † does he get by buying up broken images of persons who sell them by wholesale, and he of course gets them for little or nothing: then what does he do but dresses out his board, to give them the best appearance he can, and toddles into the streets, touting†† for a good customer. The first genteel bit of flash he meets that he thinks will dub up the possibles,∮ he dashes down the board, breaks all the broken heads, and appeals in a pitiful way for remuneration for his loss; so that nine times out of ten he gets some Johnny-raw or other to stump up the rubbish [∮ To dub up the possibles —To stand the nonsense — are nearly synonymous, and mean — will pay up any demand rather than be detained].
1836		H.M. Milner Turpin’s Ride to York ii 5: sam: Peel my skin and dub up the browns! What do you mean? bal.: Just this – that if you do not hand over your money I shall blow out your brains! [F&H].
1844		C. Selby London by Night I i: I must provide our dupe with dress, cash, and all the requirements of a gentleman – so dub up!
1845		Bell’s Life in Sydney 6 Dec. 3/3: On entering Driscoll's yard [...] he cried out ‘dub up you black b—r’.
1852		G.C. Mundy Our Antipodes I 181: The juniors are compelled to dub up, or are seized and robbed by force.
1873		Sl. Dict.
1881		N.Z. Observer (Auckland) 15 Jan. 169/1: The Rev. Mr. G. [...] flatly refused to dub up.
1881		Newcastle Courant 2 Dec. 6/6: Here’s the wash and if yer please Mrs Maguire says as how she would take it kindly if yer would dub up — I mean pay her at once.
1881		N.Z. Observer (Auckland) 22 Jan. 181/2: Whether Mr. Gittoes was or was not asked to ‘dub up’ [...] 15 per cent of his salary remains to be proved.
1885		Bulletin (Sydney) 14 Mar. 7/2: For if it be necessary that the railway officers should dub up a week’s pay, it follows that every other toiler and capitalist in the colony should do the same.
1891		Sporting Times 21 Mar. 1/4: Unless Nathaniel dubbed up ten of the best he would be locked up in the Chateau Lambert as a rogue.
1895		Crowe Aus. Sl. Dict. 25: Dub Up, pay up.
1901		‘Miles Franklin’ My Brilliant Career 259: None of us have a penny to bless ourselves with, let alone dub up for taxes.
1908		Gem 17 Oct. 4: A giddy baronet ought to be able to dub up at times.
1954		Oh Boy! No. 17 14: Now then, Ma! Dub up! This is a hold-up!
1980		Barltrop & Wolveridge Muvver Tongue 21: Callin on some one to disgorge cash, the phrase is ‘dub up’ or ‘dub out’.