Dundee United, Raith Rovers and Cove Rangers have asked Scottish Premiership clubs to pledge £5,000 each towards their costs as they defend legal action taken by Hearts and Partick Thistle.
Championship clubs have been asked to pledge £2,000 each, with League One and League Two sides asked for £1,000.
The legal action by Hearts and Thistle, which is going to arbitration, could result in United, Raith and Cove having their promotions overturned.
United say the trio have spent £50,000.
The club believes costs are expected to rise to around £150,000 in the next week when the independent arbitration panel meets to decide if Hearts' and Thistle's claim on being reinstated to the leagues or awarded damages of £10m is heard.
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On Monday, United, Raith and Cove said they hope "fans of clubs across Scotland" would contribute to a crowdfunding campaign that they planned to launch.
However, since then two United fans set up a funding page of their own and the club is now officially endorsing it instead.
The fans will walk from Hearts' Tynecastle Stadium to Tannadice on Saturday 18 July "to highlight the situation that Dundee United finds itself in".
United said: "In a continuing show of solidarity in defence of the case, we have had discussions with Raith Rovers and Cove Rangers and they will also be participating in this event with their own supporters running similar crowdfunding campaigns, and organising a walk from their stadiums in Kirkcaldy and Aberdeen to Tannadice on the same day."
Cove's fundraising is centred on a fan and two of the club's former players doing a 63-mile sponsored walk from Balmoral Stadium to Tannadice.
Hearts and Thistle initially went to the Court of Session after their relegations from the Premiership and Championship were not prevented by the SPFL's failed proposal for league reconstruction. The proposal would also have given Stranraer a reprieve from League One relegation.
Lord Clark decided the rules of the football authorities mean the case must be heard by an independent tribunal set up through the Scottish FA rules.