Marni Trevena always assumed she would get married, have children and share life's costs with a partner.Instead, at 39, she's navigating mortgages, bills and major life decisions alone, all while also contending with the emotional and financial impacts of the singles tax.The singles tax is the extra costs people pay when they can't split costs like rent, internet, insurance and other household bills the way couples can."Having to pay for everything on your own with only one income is difficult," Ms Trevena said She owns her home and has strong family support.So she's speaking out, in part, on behalf of singles who are not as fortunate."If most single people aren't saying anything, then they [policy makers] are not going to know that we feel this way," she said.Marni Trevena reached out to the ABC through Your Say to bring up the topic of a singles tax."One of the most frustrating aspects of my life, acknowledging the privilege I hold, is that I often miss out on any small element of support which will lighten the load," she said."Every year, budgets both state and federal come out and provide relief for families, pensioners and disabled people