(a) If your agency knows from the beginning of your TDY assignment that your assignment qualifies as taxable extended TDY, then your agency will withhold an amount as a WTA and pay that as withholding tax to the IRS until your extended TDY assignment ends. The WTA itself is taxable income to you, so your agency increases, or “grosses-up,” the amount of the WTA, using a formula to reimburse you for the additional taxes on the WTA.

(b) If your agency realizes during a TDY assignment that you will incur taxes (because, for example, the TDY assignment has lasted, or is going to last, longer than originally intended), then your agency will compute the WTA for all taxable benefits received since the date it was recognized that you are no longer “temporarily away from home” (see § 302-11.601 for more information on the meaning of “temporarily away from home”). Your agency will pay that amount to the IRS, and then will begin paying WTA to the IRS until your extended TDY assignment ends.

(c) For your ETTRA, your agency will use the same one-year or two-year process that it has chosen to use for the relocation income tax allowance (RITA).

(d) See part 302-17 of this subtitle for additional information on the WTA and RITA processes.