Married taxpayers filing jointly who make a balance-due payment online may find the payment not being credited to their account because they may not understand an unwritten rule, an Atlanta-based enrolled agent told Accounting Today.

When a taxpayer receives a CP-14 notice, he or she may misunderstand that a payment must be made by the primary taxpayer. Taxpayers do not understand that "primary" means first on the return, and "secondary" means second on the return, when they are paying a balance due, explained Bill Nemeth, the president and education chair of the Georgia Association of Enrolled Agents. "The same is true for estimated tax payments,” he said. “If the secondary taxpayer makes a payment in her name and social, the system will not reflect it."

"They may get a CP14 which shows a balance due and includes a voucher which has the primary taxpayer's information on it, which is supposed to go on their check (Social Security number, tax form, tax year). That works well," Nemeth explained further. "But if the taxpayer or spouse goes online to pay the balance, frequently the spouse who is second on the return will make the payment in their SSN because they were responsible for the balance due—for example, if the taxpayer is disabled and the spouse is working and therefore figures that she should pay the tax."

The IRS recognized this situation in a July 27 notice. “The IRS is aware that some payments made for 2021 tax returns have not been correctly applied to joint taxpayer accounts, and these taxpayers are receiving erroneous balance due notices (CP-14 notices) or notices showing the incorrect amount,” the notice read. “Generally, these are payments made by the spouse (second taxpayer listed) on a married filing jointly return submitted through their Online Account. Some other taxpayers may also be affected outside of this group.”

Most tax professionals know this, but taxpayers do not, Nemeth said. "It's one of the things we learn along the way when we do it wrong," he said. "But it's not spelled out on the IRS website.  … It's only mentioned if you're making a payment without logging into an account. It will show that you're making a payment as a 'guest.'"

Nemeth said that a taxpayer may have a tax preparer pay the balance, which the preparer may do as a guest. The IRS allows people to make payments without creating or logging into an account, he said.