Farmers are also able to contact IRD if they need flexibility with making tax payments. In the 2010-11 drought, fewer than 100 farmers received rural assistance payments.
Acting Prime Minister Bill English said he would not increase the amount of money available to farmers in the future.
"The actual cash support is actually very difficult to get, farmers need to be able to show extreme hardship, essentially having no money available for meeting household needs.
"There isn't any financial assistance available for their farm management decisions."
He said their main concern would be dealing with IRD.
Mr English said he didn't know how many farmers had taken up IRD's offer to be flexible with tax payments, but said hundreds would if rain didn't ease the situation.
Tararua, Wairarapa, Manawatu-Rangitikei and Taranaki are expected to be declared drought-affected shortly and a spokesman for Mr Guy said the minister was keeping a close eye on the South Island.