Poor people settled their accounts in person. The local grocer—and perhaps the butcher, baker, and greengrocer; maybe even the dry goods merchant and hardware store as well—would often offer credit to regular customers. Even the children of a household would often be known to the storekeepers, so from a young age they could be sent for needed items without having to carry money. Any merchant extending that kind of credit also knew when payday at the big local employers was, and when to expect a household's account to be brought current. For big-ticket items like furniture and appliances bought on credit, householders would make payments monthly at the neighborhood store where it was purchased. Urban utilities, such as gas and power companies, often had neighborhood storefront offices as well as a downtown one where payments could be made in cash or by check. Paperboys collected in person; insurance companies often had collectors who would go door to door to collect very small amounts week by week on life or burial insurance policies.

Middle-class families, which in 1930 would include most homeowners in urban areas, more typically had bank accounts, and so could write and mail checks. A bill would either be mailed from someplace like the mortgage holder, department store, water utility, or telephone company; or might be dropped off by the milkman or iceman with a delivery. The household then would typically have 20 days or so to pay the bill, either by paying in person at the business, or by mailing a check. Households without checking accounts could purchase money orders at supermarkets, chain drugstores, or post offices.

For those of us who grew up in the 20th century, sitting down once a week or so to pay the household's bills by writing checks and mailing them was such a familiar part of life that your question is rather startling.