kelly erb– Kelly Phillips Erb is a small business owner and practicing tax attorney at the Erb Law Firm in Philadelphia. She is also the author of the popular Tax Girl blog. The views expressed are her own. –

Chances are, you’ve already filed, as only a third of all tax returns are filed during the last week of tax season. But if you haven’t, keep these tips in mind:

- Postage rates for large envelopes went up yesterday (yes, yesterday). If you’re mailing your return – and it’s a big one – make sure to allow extra time at the post office.

- A number of post offices will be open to accommodate last-minute filers. You can find a list of those offices open past 6 p.m. EDT here (downloads as a pdf). You can also find a post office by location on the USPS website.

- You can also use a private delivery service to file your tax return or extension. The IRS considers the following private delivery services as acceptable to meet the timely filed rule: DHL Express (DHL): DHL Same Day; Federal Express (FedEx): FedEx Priority Overnight, FedEx Standard Overnight, FedEx 2Day, FedEx International Priority, and FedEx International First; United Parcel Service (UPS): UPS Next Day Air, UPS Next Day Air Saver, UPS 2nd Day Air, UPS 2nd Day Air A.M., UPS Worldwide Express Plus, and UPS Worldwide Express.