Pronunciation: [ɹˈʌn ˌʌp ɐ bˈɪl] (IPA) 
Phonetically, the spelling of "run up a bill" is /rʌn ʌp ə bɪl/. The word "run" is pronounced as /rʌn/, while "up" is pronounced as /ʌp/. "A" is pronounced as /ə/, and "bill" is pronounced as /bɪl/. "Run up a bill" means to accumulate a large amount of debt or expenses, usually due to overspending. It is important to be mindful of one's budget and expenditure to avoid running up a bill.
To "run up a bill" is a phrase used to describe the act of accumulating or increasing a debt or financial obligation by making purchases or incurring expenses that will be paid at a later date. It refers to the process of multiplying the amount owed on a bill by continuously adding charges or expenses to it, resulting in a larger total sum.
This expression commonly refers to the accumulation of charges on an account, such as a credit card, utility bill, or rental agreement. It suggests that someone has been spending money or making charges excessively, indiscriminately, or beyond their means, ultimately leading to a significant financial obligation. For example, if an individual frequently dines at expensive restaurants, shops excessively, or constantly uses their credit card without proper consideration for their financial situation, they may "run up a bill" and find themselves struggling to pay off the accumulated expenses.
The phrase can also extend beyond financial matters. It may be used metaphorically in a broader context to describe the process of accumulating or increasing any kind of obligation or problem, such as an emotional or social debt. Similarly, if someone neglects their responsibilities or acts irresponsibly in a situation, they may "run up a bill" of negative consequences or repercussions.
