Ultimately this depends on whether your job is qualified as exempt or non-exempt. In short, if you are non-exempt your employer is required to pay you for every hour worked, including overtime. Exempt employees receive a salary irrespective of their actual hours worked and the employer is largely free to put constraints on their working time however they choose. In both cases, the employer has to pay the agreed upon salary per hour or week/month, there is no legal way for a company to avoid paying employees for work performed.
Now, to expand on this in more detail, most of this is covered in the Federal Labor Standards Act of 1938. The FLSA is a federal statute that applies to most commercial organisations. Companies with a yearly gross revenue below $500,000 may be exempt but key qualifiers are listed in the act itself: FLSA - 29 U.S. Code Chapter 8, Sec. 203. Definitions (1) (A). Whether your company is covered is generally a question for a lawyer or perhaps your state labor agency.
Exempt versus non-exempt
While some jobs are classified as exempt by definition (e.g. "outside sales"), for most employees it depends on:
- how much they are paid,
- how they are paid, and
- what kind of work they do ("exempt duties")
As the FLSA states, with few exceptions, to be exempt an employee must:
- be paid at least $23,600 per year ($455 per week)1, and
- be paid on a salary basis, and also
- perform exempt job duties
1 - This number was set to change to $47,476 annually or $913 per week on December 1st 2016. For details see my answer on the changes here
Exempt duties are classified as executive, professional or administrative. Normally, meeting all three "tests" automatically qualifies an employee as exempt. Employees that are treated as exempt (i.e. receive no overtime pay) but don't meet these tests are legally considered non-exempt and can challenge their status for years after the fact. If successfully challenged, the employer will be required to pay out back pay for all the overtime the employee worked.
The FLSA also requires that a non-exempt employee is paid for overtime even if it's voluntary or the employee offers to work extra hours for free (for details see the Work Time section below). To protect employees' rights in coercive situations they cannot legally waive their right to overtime pay. It's for these reasons that business owners or HR managers should be aware of this policy and ensure that they comply fully as they can risk heavy fines or collection of back pay.
Exempt employees have "virtually no rights at all" under FLSA overtime rules while non-exempt employees are entitled to receive one and one-half times their "regular rate" for overtime, defined as each hour they actually work over the applicable FLSA overtime threshold in the applicable FLSA work period (typically 40 hours per week).
Now that that is out of the way, we come to the subject of defining work time. The FLSA covers this in detail. It's a bit wordy but I'll reproduce a section here with relevant sections highlighted:
All time spent by an employee performing activities which are job-related is potentially "work time." This includes the employee's regular "on the clock" work time, plus "off the clock" time spent performing job-related activities (which benefit the employer). Potential work is actual work if the employer "suffered or permitted" the employee to do it. An employer suffers or permits work if it knows the employee is doing the work (or could have found out by looking), and lets the employee do it.
With only a few exceptions, all time an employee is required to be at the premises of the employer is work time. All regular shift time is work time. This includes "breaks" (if there are breaks), and "nonproductive" time (for example, time spent by a receptionist reading a novel while waiting for the phone to ring). In addition, all time spent by an employee performing work-related activities that the employer suffers or permits is work time, whether on premises or not and whether "required" or not. Work done "at home" or at a place other than the normal work site is work, and the time must be counted. "Voluntary" work is work, and the time must be counted. "Unauthorized" or "unapproved" work is work and must be counted (provided that the employer knows or should know it is being done and permits the employee to do it). It is the privilege and responsibility of the employer to "control the work" of its employees. If an employer does not wish an employee to perform work, it must prohibit the employee from doing so if it does not wish to include that work time in the required FLSA pay computations. An employer may not accept the benefit(s) of work performed by its nonexempt employees without counting the time in computing pay due under the FLSA. Important FLSA regulations on these points are at 29 CFR §§785.11, 785.12, and 785.13.
"Off the clock" work
The FLSA goes on to clarify off the clock work (again, emphasis mine):
Many FLSA lawsuits have involved employers failing to include time spent by employees performing work activities outside of their normal shifts. Some employees, for example, may "come early" and start working before the official start time of their shifts. Such time counts as work time and must be included in FLSA pay computations, provided only that the employer knew or should have known that the employee was beginning work early (and, of course, to the extent that the employee spent pre-shift time actually performing work activities). Pre-shift "roll calls" are work time. Time spent setting up equipment before the official start time of a shift is work time. Some employees may similarly "stay late" after shifts performing work; this time must be counted as work time, as well. Time spent by an employee cleaning equipment after the close of a shift is work time. Post-shift work time could also include time spent by an employee performing job-related activities "on the way home," as for example a secretary who drops off the day's mail at the post office or delivers some paperwork to a customer or supplier. Some employees take work home. That time may well be work time. Similarly, if an employee is contacted at home by telephone for work related reasons, the time spent is work time (and, of course, if an employee is "called back" to work, the time counts as work time).
So let's look at your situation. We can safely assume from your description (max of 6 hours per week, standard retail work) that you qualified as non-exempt. The email you reproduced states:
PLEASE be here AT LEAST 15 minutes prior to your start time. We know things happen, and if you are going to be late, please call us to let us know.
So in summary we clearly see that pre-shift work does qualify as work time which means you should have been paid for it. Your employer explicitly requested employees to come in early, which means they would have known that employees were beginning work early. That coupled with the clear definition in the FLSA of pre-shift work as work time means you should have been paid for that time.
If they had requested you to come in 15 minutes early but not work during that time, we're in more of a grey area since you're not explicitly performing job duties but as the FLSA states " all time an employee is required to be at the premises of the employer is work time".
In closing, if you feel comfortable doing so, consider contacting either your former colleagues or the company and advise them of the requirements that the FLSA places on companies employing non-exempt staff. It could be that local management is simply ignorant of the law and if it's a large chain their HR team will be quick to sort this out. If they persist in refusing to count this time as working time, your former colleagues should contact a lawyer or your state labor agency which is generally good at following up on these issues.
Necessary disclaimers: I am not a lawyer and this post does not aim to give legal advice. It is merely intended to summarise the contents of the FLSA. The linked site (FLSA.com) seems to be commercial in nature but is run by registered attorneys and the pages linked seem to summarise the FLSA correctly.