Manager Paolo Di Canio has revealed Swindon are under a transfer embargo.
The Italian told BBC Wiltshire after Saturday's 1-0 win over Bury the embargo had been sanctioned because they had overspent on wages and fees.
Financial Fair Play rules state League One clubs must limit their wage and fee bill to 65% of their turnover.
They exceeded this restriction after a tribunal demanded they pay a combined fee of Â£340,000 for James Collins and Troy Archibald-Henville.
More: BBC Sport